501) When a stone is thrown in the calm water of a pond the waves produced on the surface of water in the pond are –
Answer
transverse
502) A cyclone is an engineering device that is used to -
Answer
segregate particles
503) The density of water is 1 g/cc. This is strictly valid at –
Answer
4°C
504) In an electric motor, the energy transformation is from _.
Answer
electrical to mechanical
505) A radioactive substance does not undergo any change (in mass or charge) during –
Answer
gamma-emission
506) On a rainy day, small oil films on water show brilliant colors. This is due to -
Answer
interference
507) The waveform of a certain signal can be studied by –
Answer
Sonometer
508) Ultrasonic waves are produced by making use of -
Answer
piezo electric material
509) Least audible sound for most of the human ear is –
Answer
0.0002 μ bar
510) Amount of water vapour (gaseous) in a given volume of air (cubic metre) is known as:
Answer
Absolute humidity
511) The opening and closing of the stomatal pores is a function of the -
Answer
Guard cells
512) In the remote control of television, electromagnetic waves used are –
Answer
infrared
513) Heat flows as a result of difference of _.
Answer
Temperature
514) Sound and light waves both _.
Answer
obey the laws of reflection
515) Radioactive elements can be traced out in living cell through a technique called –
Answer
Auto radiography
516) Human beings can hear the sound range between:
Answer
None of the above
517) Solids which conduct electricity at higher temperature but not at lower temperature are called –
Answer
semi-conductor
518) In a filament type light bulb most of the electric power consumed appears as –
Answer
infra-red rays
519) Optical fibre works on the principle of –
Answer
total internal reflection
520) The colours of stars depend on their –
Answer
temperature
521) Water has maximum density at –
Answer
4°C
522) Hydraulic brakes work on the principle of –
Answer
Pascal's law
523) X- rays are waves.
Answer
Electromagnetic
524) Which planet is nearest to the sun?
Answer
Jupiter
525) The moon that we see in the sky is a .
Answer
Satellite
526) The absolute zero is a temperature at which _.
Answer
molecular motion in a gas would cease
527) The term "infrasonic" applied to sound refers to sound waves below -
Answer
20 Hz
528) If no external force acts on a system of bodies, the total linear momentum of the system of bodies remains constant. Which law states that?
Answer
Principle of conservation of linear momentum
529) A body moving in a circular path with a constant speed has a –
Answer
constant kinetic energy
530) The Solar energy produced by –
Answer
Fusion reaction
531) In which form is the supplied heat energy stored during change in temperature of substance?
Answer
Kinetic energy
532) The large collection of stars, dust and gas held together by gravitational attraction between components is known as –
Answer
Galaxy
533) The working of a rocket is based on the principle of:
Answer
Conservation of momentum
534) Light waves projected on oil surface show seven colours due to the phenomenon of -
Answer
interference
535) Which variety of glass is heat resistant?
Answer
Pyrex glass
536) The waves used in sonography are –
Answer
Ultrasonic waves
537) The sky appears blue due to –
Answer
Rayleigh scattering
538) The device used to convert solar energy into electricity is –
Answer
Photovoltaic cell
539) If two bodies of different masses, initially at rest, are acted upon by the same force for the same time, then the both bodies acquire the same -
Answer
momentum
540) The absorption of ink by blotting paper involves -
Answer
capillary action phenomenon
541) A fuse wire is made of:
Answer
an alloy of tin and lead
542) Ultra violet light of Sun's radiation is prevented from reaching the earth's atmosphere by the layer of –
Answer
Ozone
543) Which instrument is used to measure depth of ocean?
Answer
Fathometer
544) When a running car stops suddenly, the passengers tends to lean forward because of:
Answer
inertia of motion
545) Why the Earth is having its own atmosphere?
Answer
Gravity
546) A ray of white light strikes the surface of an object. If all the colours are reflected, the surface would appear
Answer
White
547) It is difficult to walk on ice because of .
Answer
absence of friction
548) One bar is equal to –
Answer
10⁵ Pa
549) A NOT gate can be implemented by:
Answer
a single transistor
550) Persistence of vision is the Principle behind:
Answer
Cinema
551) Sudden fall in barometer is indication of -
Answer
Tide
552) If in a motion, the axis of the rotation does not pass through the object, then the motion is called -
Answer
Orbital motion
553) Supercooling is cooling of liquid _.
Answer
below freezing point
554) How can we measure specific gravity of milk?
Answer
Using a hydrometer
555) The base of an electric iron is brightly polished mainly -
Answer
to reduce heat loss by radiation
556) Oparin's theary about origin of life' is related to -
Answer
chemical evolution
557) Heat given to a body which raises its temperature by 1°C is known as -
Answer
thermal capacity
558) Flemings "Left hand Rule" is associated with the effect of –
Answer
Magnetic Field on current
559) The force which makes a vehicle to stop when break is applied is called –
Answer
frictional force
560) In radio-communication, the signals emitted by transmitting antenna are reflected on –
Answer
ionosphere
561) While cooking, if the bottom of the vessel is getting blackened on the outside, it means that -
Answer
The fuel is not burning completely
562) If electrical conductivity increases with the increase of temperature of a substance, then it is a -
Answer
Semiconductor
563) Automatic wrist watches get energy from -
Answer
twist in spring
564) Radian is used to measure -
Answer
Angle
565) Light year is a unit of –
Answer
Distance
566) The word 'insulation' means –
Answer
incoming solar radiation
567) An object with a constant speed –
Answer
is not accelerated
568) The instrument used to regulate temperature to a particular degree is called :
Answer
Thermostat
569) The technique used by bats to find their way or to locate food is _.
Answer
Echolocation
570) In the absence of the earth's atmosphere, sky would appear –
Answer
black
571) If ice floating on water in a vessel melts, the water level in the vessel -
Answer
does not change
572) One micron is equal to-
Answer
1/1000th of mm
573) Quality of a musical note depends on –
Answer
Harmonics present
574) The frequency of direct current is .
Answer
Zero
575) For photoelectric effect to take place, the metal used as the cathode should have –
Answer
low work function
576) If electric resistance is to be decreased, then the number of resistances should be connected in –
Answer
Parallel
577) The material used in electric heater is –
Answer
Nichrome
578) The rate of change of displacement is called:
Answer
Velocity
579) The direction of heat flow between two objects depends on -
Answer
Their temperatures
580) A man in a train moving with a constant velocity drops a ball on the platform. The path of the ban as seen by an observer standing on the platform is –
Answer
A parabola
581) While ascending a hill, the driver of the vehicle keeps the gear ratio –
Answer
either equal to or greater than 1
582) A wire of resistance R is cut into ‘n’ equal parts. These parts are then connected in parallel. The equivalent resistance of the combination will be –
Answer
R/n²
583) What is unit of Electrical Capacity?
Answer
farad
584) Work done upon a body .
Answer
only a scalar quantity
585) With the increase of pressure, the boiling point of any substance -
Answer
Increases
586) Supersonic plane fly with the speed -
Answer
greater than the speed of sound
587) When a particle and an antiparticle come in contact with each other, they -
Answer
annihilate each other
588) Photon is the fundamental unit/ quantum of –
Answer
light
589) Time of exposure required for taking photograph of an object depends upon the –
Answer
brightness of the object
590) The ordinary and maximum tolerance limit of sound by human being is –
Answer
60 db to 80 db (decibel)
591) Which is best used as a sound absorbing material in partition walls?
Answer
Glass - wool
592) Light Emitting Diodes (LED) is used in fancy electronic devices such as toys emit
Answer
radio waves
593) The primary colours in photography are –
Answer
Red, Blue, Yellow
594) Stress can be defined as quantity.
Answer
Tensor
595) Vehicles use to see the objects coming from behind.
Answer
Convex lens
596) If electrical conductivity increases with the increase of temperature of a substance, then it is a:
Answer
Semiconductor
597) Transition ions absorb light in –
Answer
visible region
598) If a body weighs 12N on the surface of the earth, how much will it weigh on the surface of the moon where acceleration due to gravity is only one-sixth of that on earth's surface?
Answer
2N
599) 'Kilowatt-hour' is the unit of -
Answer
electric energy
600) One micron is equal to-
Answer
1/1000th of mm
601) If the temperature inside a room is increased, the relative humidity will ?
Answer
decrease
602) The device used to change the speed of an electric fan is -
Answer
Regulator
603) The required DC voltage for arc welding is-
Answer
200 to 250 V
604) What is the base of the Octal Numeral System?
Answer
8
605) A wire carrying current is –
Answer
neutral
606) A light ray travelling from denser to rarer medium at an angle of incidence more than critical angle of concerned media pair suffers.
Answer
total internal reflection
607) Respiration in the absence of air is called -
Answer
Anaerobic respiration
608) An alloy is an example of :
Answer
Solid solution
609) Hydrogen atom is excited from ground state to another state with principal quantum number equal to 4. Then the number of spectral lines in the emission spectra will be -
Answer
6
610) The resistance of a conductor is inversely proportional to its -
Answer
area of cross section
611) is the perpendicular distance between point of application of force and axis of rotation.
Answer
Moment arm
612) The rotational effect of a force on a body about an axis of rotation is described in terms of the –
Answer
Moment of force
613) An object is placed on the principal axis of a convex lens of focal length 10 cm. If the distance of the object from the lens is 30 cm, what is the distance of the image formed?
Answer
15 cm
614) A moving neutron collides with a stationary α-particle. The fraction of the kinetic energy lost by the neutron is –
Answer
16/25
615) Which of these waves can be polarized?
Answer
Light waves
616) X-rays are –
Answer
neutral particles
617) An a-particle is .
Answer
A helium nucleus
618) What type of lens is used to correct vision of a person suffering from Myopia?
Answer
Concave lens
619) What is the name of the device used to convert alternating cur-rent into direct current?
Answer
Rectifier
620) A light year is a unit of:
Answer
Distance
621) The SI unit of luminous emittance is -
Answer
Lux
622) Total internal reflection cannot take place when light goes from –
Answer
water to glass
623) Hertz is a unit for measuring –
Answer
Frequency of waves
624) The unit of Planck's constant is –
Answer
Js
625) If a wire of resistance R is melted and recast to half of its length, then the new resistance of the wire will be -
Answer
R/4
626) Clouds float in the atmosphere because of their –
Answer
low density
627) Removal of carbon particles from air involves the principle of -
Answer
Electrophoresis
628) The focal length of a plane mirror is .
Answer
Infinity
629) The wire having a green plastic covering is a .
Answer
Earth wire
630) The centre of the reflecting surface of a spherical mirror is called the :
Answer
Pole
631) If a bomb dropped from an airplane explodes in mid-air .
Answer
its KE increases
632) The phenomenon of radioactivity was discovered by -
Answer
Henri Becquerel
633) Energy travels from Sun to Earth through –
Answer
radiation
634) Rain drops acquire spherical shape due to -
Answer
surface tension
635) Pieces of camphor placed on water move about rapidly. This is because of -
Answer
surface tension
636) What does the symbol R in electricity stand for?
Answer
Resistance
637) The velocity of light in vacuum is :
Answer
3 * 108 ms-1
638) Why does a black board appears black in color?
Answer
It absorbs all the colours
639) The pitch of the sound is measured by its:
Answer
Frequency
640) Intensity of sound has -
Answer
an object existence
641) The south pole of the earth’s magnet is near the geographical .
Answer
north
642) Ozone layer above the surface of Earth provides a shield against –
Answer
Ultra-violet rays
643) The Newton's First Law is also called as –
Answer
Law of inertia
644) Fat can be separated from milk in a cream separator because of _.
Answer
centrifugal force
645) A charge of 2C passes from one point to the other in a circuit. If the potential difference between the two points is 5V, the amount of work done is :
Answer
10 J
646) The large collection of Stars, dust and gas held together by gravitational attraction between components is known as
Answer
Galaxy
647) An amplifier is said to suffer from distortion when its output is -
Answer
noisy
648) While catching a ball, a player pulls down his hands to lower the -
Answer
momentum
649) Optical fibres are mainly used in -
Answer
Communication
650) Radiocarbon dating technique is used to estimate the age of -
Answer
fossils
651) 'Parsec' is the unit measurement of -
Answer
Astronomical distance
652) Receptors used to detect taste are known as -
Answer
Gustatory receptors
653) Tesla is a unit of magnetic –
Answer
field
654) The damage of the human body due to radiation (X-rays or y-rays etc,) is measured in –
Answer
Rems
655) Golden view of sea shell is due to -
Answer
Polarization
656) An object covers distance which is directly proportional to the square of the time. Its acceleration is –
Answer
constant
657) What is impulse equal to?
Answer
Change in momentum
658) The person suffering from “myopia” cannot see the objects at:
Answer
Longer distance
659) When water freezes its density –
Answer
Decreases
660) The element required for Solar energy conversion -
Answer
Silicon
661) The washing machine works on the principle of –
Answer
Centrifugation
662) The 'Choke' used with a tube light is basically –
Answer
an inductor
663) The temperature of a liquid is 32° F. What is its temperature in Celsius scale?
Answer
0° C
664) Plank's constant has the dimensions of :
Answer
energy
665) When number of turns in a coil is tripled, without any change in the length of coil, its self inductance becomes?
Answer
Nine times
666) The abbreviation LHC stands for which machine?
Answer
Large Hadron Collider
667) In a particular system, the units of length, mass and time are chosen to be 10 cm, 10 g and 0.1 s respectively. The unit of force in this system will be equivalent to –
Answer
0.1 N
668) Relative humidity is expressed as –
Answer
Percentage
669) Why is weightlessness experienced while orbiting the earth in space ships?
Answer
None of these
670) Where is a transistor most likely to be found?
Answer
Hearing aid
671) What is the SI unit of electric current?
Answer
Amperes
672) An object is in static equilibrium when it is .
Answer
at rest
673) Equal volumes of different gases at any definite temperature and pressure have-
Answer
equal no. of molecules
674) Which law states, "The rate of loss of heat by a body is directly proportional to the difference in temperature between the body and the surroundings"?
Answer
Newton's law of cooling
675) Every hot object emits –
Answer
Infrared rays
676) Postage Meter was invented by -
Answer
Arthur Pitney
677) A solid ball of metal has a spherical cavity inside it. When the ball is heated the volume of the cavity will -
Answer
increase
678) When two semiconductors of p-and n-type are brought in contact, they form p-n junction which acts like a/an –
Answer
Rectifier
679) Ohm's law is valid in case of –
Answer
conductor
680) The freezing point of fresh water is -
Answer
0°C
681) The unit of noise pollution (level) is –
Answer
decibel
682) The boiling point of water decreases at higher altitudes is due to –
Answer
low atmospheric pressure
683) The reactivity of an ionic compound element is explained as its tendency to attain noble gas configuration. How do the elements do so?
Answer
Both are correct
684) A water tank appears shallower when it is viewed from top due to –
Answer
refraction
685) For a ray of light to suffer total internal reflection it has to pass from –
Answer
air to water
686) A solid needle placed horizontally on the surface of the water floats due to –
Answer
surface tension of water
687) The first equation of motion gives the relation between :
Answer
Velocity and time
688) What is the minimum distance (in metres) required to hear an echo?
Answer
17
689) The intensity ratio of waves is 25:9. What is the ratio of their amplitudes?
Answer
5 : 3
690) Which of these travels in glass with minimum velocity?
Answer
violet light
691) The phenomenon which causes mirage is –
Answer
Total internal reflection
692) Heat is transmitted from higher temperature to lower temperature through the actual motion of the molecules in –
Answer
Convection
693) The commonly used coolant in refrigerators is –
Answer
Freon
694) The term ‘Higgs Boson’ is associated with -
Answer
God Particle
695) Kilowatt-hour (KWH) is the unit of -
Answer
energy
696) Major portion of the earth’s crust is mainly constituted by -
Answer
Oxygen and Silicon
697) The mirror used by ENT specialist is:
Answer
Concave mirror
698) Fibre optics work on the principle of -
Answer
total internal reflection
699) The reverse effect of X-ray emission is –
Answer
Photoelectric
700) The group of solar cells joined together in a definite pattern is called a –
Answer
Solar cell panel
701) Fuse wire is made of an alloy of –
Answer
Tin and Lead
702) The colour of the ocean appears to be blue because the sunlight falling on it is –
Answer
scattered
703) The least distance of distinct vision is –
Answer
25 cm
704) Sound waves can be transmitted by any –
Answer
Medium
705) Which term is not associated with sound wave?
Answer
Candela
706) If an electron and a photon have the same wavelength, then they will have the same –
Answer
linear momentum
707) In hydel power station, the motion produced in turbines is due to –
Answer
flow of water
708) The point where total mass of a body is supposed to be concentrated is known as –
Answer
Centre of mass
709) Curie is an unit of –
Answer
Radioactivity
710) The mass of an electron in motion depends upon -
Answer
B its velocity
711) Water drops cannot stick to the oily surface due to –
Answer
surface tension
712) Decibel is the unit of .
Answer
Intensity of sound
713) Magnetic keepers are pieces of –
Answer
Soft iron
714) Certain substances loose their electrical resistance completely at super low temperature. Such, substances are called.
Answer
Super conductors
715) In a transistor, the base is _.
Answer
a conductor of low resistance
716) Sound waves are produced by -
Answer
Vibrating bodies
717) The weight of a body acts through the centre of –
Answer
gravity
718) A wheel-barrow is an example of –
Answer
class II lever
719) The work done by the string of a simple pendulum during one complete oscillation is equal to –
Answer
Zero
720) The minimum number of forces to keep a particle in equilibrium is –
Answer
2
721) Which instrument is used to record the speed of a vehicle?
Answer
Speedometer
722) Human ear responds to intensities in range -
Answer
10-12Wm-2 to 1Wm-2
723) Speed of sound in air depends on the -
Answer
Physical conditions
724) The redness in atmosphere at Sunrise and Sunset is due to –
Answer
Scattering of light
725) Person who is colorblind cannot distinguish between –
Answer
Red and green
726) When we see an object, the image formed on the retina is –
Answer
Real and inverted
727) The most malleable metal is -
Answer
gold
728) If density of oxygen is 16 times that of hydrogen, what will be their corresponding ratio of velocity of sound?
Answer
1 : 4
729) S.I. unit of Magnetic flux is –
Answer
weber
730) Convex mirror is generally used in -
Answer
rear view mirror
731) A needle or a pin floats on the surface of water because of –
Answer
Surface tension
732) An object which absorbs all colours and reflects none appears:
Answer
Black
733) Alfred Nobel invented -
Answer
Dynamite
734) Instrument used to study the behaviour of a vibrating siring is :
Answer
Sonometer
735) The mass of water vapour per unit volume of air is known as -
Answer
absolute humidity
736) If a carrier wave of 1000 kHz is used to carry the signal, the length of transmitting antenna will be equal to .
Answer
300 m
737) The oil in the wick of an oil lamp rises up due to:
Answer
capillary action
738) Electrostatic precipitator is used to control –
Answer
Air Pollutants
739) The Newton's First Law is also called as –
Answer
Law of inertia
740) Hydraulic machines work under the principle of –
Answer
Pascal’s law
741) The scientist who first discovered that the Earth revolves round the Sun was -
Answer
Copernicus
742) The type of minor used in automobiles to see the traffic on the rear side is –
Answer
Convex
743) Lognitudinal waves and Transverse waves are types of -
Answer
Mechanical waves
744) The brightest planet is .
Answer
Venus
745) Sound in TV is modulating -
Answer
AM
746) Density of water is maximum at .
Answer
4 degree Celsius
747) Formation of shadows can be explained by -
Answer
rectilinear propagation of light
748) A liquid disturbed by stirring comes to rest due to –
Answer
viscosity
749) In Astrophysics, what name is given to a hypothetical hole in outer space from which stars and energy emerge?
Answer
White hole
750) The Laser is a beam of radiations which are –
Answer
Coherent and monochromatic
751) Ice float on water because its density is -
Answer
less than water
752) Distances of stars are measured in –
Answer
Light year
753) Loudness of sound depends on –
Answer
Amplitude
754) A man jumping out of a moving train is thrown -
Answer
forward
755) Blowing Air with open pipe is an example of –
Answer
Isobaric process
756) The amount of matter in a ball of steel is its –
Answer
Mass
757) When temperature difference between liquid and its surroundings is doubled, the rate of loss of heat will:
Answer
double
758) The weight of a body at the centre of earth is:
Answer
zero
759) The component used for tuning a radio is basically a variable –
Answer
Condenser
760) 0°K, is equivalent to –
Answer
-273°C
761) What type of force acts on a car moving around a curve?
Answer
Centripetal force
762) Which °fine metals has the maximum thermal conductivity?
Answer
Silver
763) What do radioactive substances emit?
Answer
α, β and γ rays
764) The term ‘Higgs Boson' is associated with –
Answer
God Particle
765) Addition of suitable impurities into semiconductor, is called –
Answer
Doping
766) When a ship enters the sea from a river what will be the effect?
Answer
It rises a little
767) Hydroscope is an instrument that shows changes in:
Answer
None of these
768) Unit of resistance is –
Answer
volt/ampere
769) A cycle tyre bursts suddenly. This represents an –
Answer
Adiabatic process
770) Which is best used as a sound absorbing material in partition walls?
Answer
Glass – wool
771) The dimensional formula ML⁻¹T⁻² corresponds to –
Answer
Modulus of elasticity
772) Purity of a metal can be determined with the help of –
Answer
Archimedes principle
773) If both the mass and the velocity of a body is increased to twice of their magnitude, the kinetic energy will increase by –
Answer
4 times
774) Which phenomenon is responsible for the echo of sound wave?
Answer
Reflection
775) A fresh egg when placed in salt water will –
Answer
float
776) What is the unit of relative density?
Answer
It has no unit
777) Hydraulic brakes in automobile work on –
Answer
Pascal's principle
778) The gas used in a refrigerator is -
Answer
cooled down when expanded
779) The main purpose of the spacecraft "messenger" is :
Answer
Mapping and investigating the Mercury
780) Light scattering takes place in –
Answer
Colloidal solutions
781) The term reactor referred to in waste water treatment is –
Answer
Aeration tank
782) The dimension MLT⁻² corresponds to –
Answer
force
783) Good conductors have many loosely bound _.
Answer
electrons
784) Cactus is referred to as -
Answer
Xerophyte
785) What is the physical state of water at 12° C?
Answer
Liquid
786) Change in quality of environment that can be harmful and unpleasant for living things is called –
Answer
Pollution
787) The element of Electric stove is made of -
Answer
Nicrome
788) Who invented the Centigrade scale?
Answer
Anders Celsius
789) Which unit we use to express nuclear sizes?
Answer
Fermi
790) Which law states, "The rate of loss of heat by a body is directly proportional to the difference in temperature between the body and the surroundings."
Answer
Newton's law of cooling
791) The constant temperature, the product of pressure and volume of a given amount of a gas is constant . This is .
Answer
Boyle’s law
792) The device used for measuring the wavelength of X-rays is –
Answer
Bragg Spectrometer
793) If a lift is going up with acceleration, the apparent weight of a body is -
Answer
More than the true weight
794) Centigrade and Fahrenheit temperatures are the same at –
Answer
-40°
795) Two bodies kept at a certain distance feel a gravitational force F to each other. If the distance between them is made double the former distance, the force will be -
Answer
F/4
796) 1 Micron is equal to –
Answer
10⁻⁶ m
797) A wavelength of 0.3 m is produced in air and it travels at a speed of 300 m/s. Then it will be an –
Answer
Audible wave
798) Which instrument is used to measure altitudes in aircraft’s?
Answer
Altimeter
799) When an object is heated, the molecules of that object -
Answer
began to move faster
800) In which region of electromagnetic spectrum does the Lyman series of hydrogen atom lie?
Answer
Ultraviolet
801) A light wave is incident over a plane surface with velocity x. After reflection the velocity becomes-
Answer
x
802) The magnitude of current flowing between two end points of a conductor is proportional to the potential difference between them and is called as:
Answer
Ohms law
803) At low temperature, Lead behaves as a –
Answer
Super conductor
804) The mean distance from the Sun to the Earth is called:
Answer
Astronomical Unit
805) “Curie” is the unit of –
Answer
radioactivity
806) Sending a frame to a group of stations is known as –
Answer
Multicasting
807) The fuse in an electric circuit is connected in –
Answer
series with live
808) A particle is thrown vertically upward. When it reaches the highest point, it has –
Answer
a downward acceleration
809) The spring balance works on the principle of -
Answer
Hooke's Law
810) Fill in the blank with the most appropriate option. The Universal Constant of Gravitation is _.
Answer
6.67 x 10⁻¹¹ Nm²/kg²
811) A moving car possesses -
Answer
mechanical energy
812) Which Article of the Indian Constitution provides free and compulsory education to children?
Answer
21-A
813) The cooling by a desert Cooler is based on:
Answer
Evaporative Cooling
814) Distant objects are visible as a little out of focus in this condition –
Answer
myopia
815) That an Iron ship floats in water but an Iron ball sinks, is an example of -
Answer
Archimedes Principle
816) A temperature rise in environment that disturbs life is called -
Answer
thermal pollution
817) What is the approximate height of a geostationary satellite from the surface of the earth?
Answer
35000 km
818) What is the SI unit of frequency?
Answer
Hertz
819) The metallurgical process in which a metal is obtained in a fused state is called -
Answer
smelting
820) Weight of a person at a height of 2R from the centre of the earth, where R is the radius of the earth-
Answer
becomes one-fourth
821) The dimensional formula for universal gravitational constant is –
Answer
M⁻¹L³T⁻²
822) Alpha particle is the nucleus of an atom of –
Answer
Helium
823) 'Farad' is the unit of :
Answer
Capacitance
824) Man perceives sound vibrations in the frequency ranges of –
Answer
20 - 20000 Hz
825) The quantum theory of light was given by -
Answer
Plank
826) The earth is a –
Answer
good absorber and good radiator of heat
827) Which law states, “The rate of loss of heat by a body is directly proportional to the difference in temperature between the body and the surroundings.”
Answer
Newton’s law of cooling
828) Why does water tank appear shallower when viewed from the top?
Answer
Due to refraction
829) Which colour is formed when Red and Green are mixed?
Answer
Yellow
830) A water tank appears shallower when it is viewed from top due to –
Answer
refraction
831) The quality or tone of a musical sound produced by a stringed instrument depends on –
Answer
wave form of the sound
832) Rocket works on the principle of –
Answer
Newton's Third Law
833) Water is used in hot water bags because –
Answer
It has high specific heat
834) The motion of the wheels of a bullock-cart while moving on the road is an example of –
Answer
Translatory and rotatory motion
835) Acceleration is –
Answer
Inversely proportional to force
836) A bomb explodes on the moon. You will hear its sound on earth after –
Answer
You cannot hear the sound of explosion
837) One nanometer is equal to
Answer
10 raised to the power (-9)
838) Magnetic keepers are used to protect magnets from :
Answer
self-demagnetization
839) When we hear a sound, we can identify its source from .
Answer
the overtones present in the sound
840) What are the two kinds of Rotatory motion?
Answer
Spin and Orbital motion
841) If lift is going up with acceleration, the apparent weight of a body is -
Answer
more than the true weight
842) A galvanometer can be converted into a voltmeter by connecting with it a –
Answer
high resistance on series
843) One nanometer is equal to meters.
Answer
10 raised to the power (-9)
844) What is the objective of the Kyoto Protocol?
Answer
To reduce greenhouse gases
845) Rainbow is formed due to –
Answer
refraction and reflection
846) Water is used in a hot water bag because –
Answer
It has high specific heat
847) A fountain pen works on the principle of –
Answer
Capillary action
848) The fundamental scientific principle in the operation of battery is –
Answer
dissociation of electrolytes
849) Velocity of sound in air does not change with the change of –
Answer
Pressure of air
850) The stability of a pond ecosystem depends on -
Answer
producers and consumers
851) Before X-ray examination (coloured X-ray) of the stomach, patients are given suitable salt of barium because.
Answer
barium is a good absorber of X-rays and helps stomach to appear clearly
852) Convex mirrors are used as a rear view mirror in motor cycles because
Answer
it forms smaller image as compared with object
853) Railway tracks are banked on curves so that –
Answer
Necessary centripetal force may be obtained from the horizontal component of the weight of the train
854) What is the range of mercury thermometer?
Answer
-30 degree Celsius to 350 degree Celsius
855) The width of depletion layer of a P-N junction –
Answer
is increased under reverse bias
856) Ventilators are provided near the ceiling of the room because –
Answer
the exhaled warmer air rises up and goes out
857) What Is a neuron?
Answer
Basle unit of nervous system
858) Why the needle of iron swims on water surface when it is kept gently?
Answer
due to surface tension
859) The spoon dropped by an astronaut in a satellite will –
Answer
Continue to follow the motion of the satellite
860) Stars appears to move from east to west because -
Answer
the earth rotates from west to east
861) The purpose of choke in a fluorescent lamp is –
Answer
to decrease the current flow
862) To prevent damage from lightning, lightning conductors are used on tall structures. The lightning conductor –
Answer
should be made of a good conductor like copper with sharp-pointed edges
863) Beta rays emitted by a radioactive material are –
Answer
Charged particles emitted by nucleus
864) What is the principle of a life Jacket'?
Answer
It increases the volume of the person to keep him afloat
865) Steam at 100°C causes more severe burns than water at 100° C because –
Answer
steam has latent heat of vaporization
866) Ice cubes are added to a glass of pure water and a glass of pure alcohol. The ice would be –
Answer
at a higher level in water
867) Indicate the false statement about the resistance of a wire –
Answer
it is directly proportional to the area of cross-section of wire
868) A metal ball and a rubber ball, both having the same mass, strike a wall normally with the same velocity. The rubber ball rebounds and the metal ball does not rebound. It can be concluded that –
Answer
The rubber ball suffers greater change in momentum
869) In a conductor –
Answer
the valence band and the conduction band overlap each other
870) On a clean glass plate a drop of water spreads to form a thin layer whereas a drop of mercury remains almost spherical because –
Answer
Cohesion of mercury is greater than its adhesion with glass
871) The mass-energy relation is the outcome of –
Answer
special theory of relativity
872) Which set of conditions represents the easiest way to liquefy a gas?
Answer
Low temperature and high pressure
873) A person can jump higher on the moon's surface than on the earth because –
Answer
the acceleration due to gravity in moon is smaller than that on the earth.
874) Rectifiers are used to convert -
Answer
Alternating current to Direct current
875) A dynamo is used to convert –
Answer
mechanical energy into electrical energy
876) Absolute Zero is defined as –
Answer
The temperature at which all molecular motion ceases
877) When a ring of metal is heated what happens to its hole?
Answer
expands
878) Red is used as an emergency or danger signal as –
Answer
its wavelength is the longest
879) The dynamo converts –
Answer
mechanical energy into electrical energy
880) A small drop of oil spreads over water because :
Answer
water has a higher surface tension
881) A small gap is left at the joints of rails in a railway track to –
Answer
avoid the tracks being distorted due to seasonal temperature variation
882) Super conductors are substances that –
Answer
offer minimum resistance to flow of electric current
883) Cloudy nights are wanner compared nights, because clouds mainly –
Answer
Reflect back the heat given by earth
884) Kepler's law of planetary motion states that the square of the time period is proportional to the –
Answer
cube of the semi-major axis
885) Spring tides occur when:
Answer
the moon, the sun and the earth are in the same line
886) When a ship enters the sea from a river –
Answer
It rises a little
887) Why are we able to hear short wave broadcasts better than long wave broadcasts?
Answer
Short waves are more energetic than long waves
888) In severe winter, in cold countries water pipes burst because –
Answer
Water expands on freezing
889) A television channel is characterized by –
Answer
frequency of transmitted signal
890) Heat energy of an object is -
Answer
The total energy of the molecules of the object
891) If a body moves with a constant speed in a circle –
Answer
its velocity remains constant
892) A white and smooth surface is –
Answer
bad absorber and good reflector of heat
893) It is easier for a man to swim in sea water, than in river water because –
Answer
the density of sea water is more than the density of river water
894) In the pressure cooker, cooking is faster because the increase in vapour pressure -
Answer
increases the boiling point
895) Kinetic energy depends on –
Answer
both mass and velocity of the moving body
896) The apparent weight of a man in a lift is less the real weight when –
Answer
the lift is going down with an acceleration
897) Plants are dried up in winter due to frost because –
Answer
There is mechanical loss of tissues and drought condition prevails
898) White clothes are cooler than black ones because they –
Answer
reflect all the light that reaches them
899) Sound is heard over longer distances on rainy days because –
Answer
sound travels faster in moist air
900) Rectifiers are used to convert -
Answer
Alternating current to Direct current
901) A galvanometer can be converted to a voltmeter by connecting –
Answer
a high resistance in series
902) Copper wires are generally used for electrical power transmission instead of iron wire because –
Answer
copper is a better conductor of electricity than iron
903) The natural environment refers to -
Answer
The living organisms and non-living objects or factors in an area undisturbed by human activity
904) Rainbows are produced when sunlight -
Answer
Incident on rain drops hanging in the atmosphere is dispersed after suffering refraction and internal reflection.
905) The information of brilliant colors in a thin soap film is a consequence of the phenomena of -
Answer
Multiple reflection and interference
906) Purpose of an optical filter is to –
Answer
transmit or absorb light of different colours
907) Why are covalent compounds poor conductors of electricity?
Answer
Due to the absence of charged particles.
908) Railway tracks are banked on curves so that :
Answer
necessary centripetal force may be obtained from the horizontal component of the normal reaction due to track.
909) An electron microscope gives higher magnifications than an optical microscope, because –
Answer
The wavelength of electrons is smaller as compared to the wavelength of visible light
910) Nichrome wire is used in an electric heater because .
Answer
For all of the above reasons
911) A concave lens always forms –
Answer
a virtual image
912) Ondometer is a -
Answer
Measuring instrument for frequency of electromagnetic waves
913) Specific gravity is defined as the ratio of –
Answer
density of the substance to the density of water
914) What are the two kinds of Rotatory motion?
Answer
Spin and Orbital motion
915) The first law of thermodynamics is simply the case of –
Answer
The law of conservation of energy
916) If you look into a mirror and find that the image (your reflexion) is smaller than you, then the type of the mirror is -
Answer
convex mirror
917) In an optical fibre the signal is transmitted –
Answer
due to total internal reflection
918) At boiling point of liquids, its :
Answer
Timperature remains increases
919) Transformer is a device to convert –
Answer
Low voltage A.C. into high voltage A.C.
920) Why does ice covered in sawdust ct melt quickly?
Answer
Sawdust is a bad conductor of heat
921) A man standing close to the platform at a railway station experiences a pulling force towards a fast moving train because of _.
Answer
pressure difference due to fast moving air in between
922) We feel cool when we sit near the fan, this is because –
Answer
air vapourises the sweat on our body.
923) The average kinetic energy of the molecules of an ideal gas is directly proportional to –
Answer
Absolute temperature of the gas
924) When heated from 0°C to 100°C volume of a given mass of water will –
Answer
Decrease and then will Increase
925) Clothes keep us warm in winter because they :
Answer
prevent the heat of the body from escaping
926) In a refrigerator what produces the cooling?
Answer
None of these
927) Microphone is a device which transforms the –
Answer
sound signal into current signal
928) Pressure Cooker cooks faster because –
Answer
higher temperature is attained for cooking
929) What is a compound microscope?
Answer
A microscope that has two sets of lenses : an occular lens and an eyepiece.
930) The temperature of boiling water in a steam engine may be high because -
Answer
there is high pressure inside the boiler
931) The motion of a body around a circular path is an example of –
Answer
Uniform velocity, variable acceleration
932) A gas thermometer is more sensitive than a liquid thermometer because a gas:
Answer
does not change state easily
933) Outside of cooking utensils are generally left black from below because –
Answer
black surface is a good absorber of heat.
934) X-rays region lies between –
Answer
Gamma-rays and ultraviolet region
935) A star appears twinkling in the sky because of –
Answer
refraction of light by atmosphere
936) Water pipes in hilly areas often burst on a cold frosty night, because –
Answer
Water in the pipes freezes and on freezing water expands, so pipes break
937) A parachute descends slowly whereas a stone dropped from the same height falls rapidly, because–
Answer
A parachute has a larger surface area and air resistance is more
938) In electronics what comes under tank circuit?
Answer
Capacity and inductance
939) In the process of magnetization of a bar –
Answer
The entire bulk of the bar gets magnetized
940) A photoelectric cell converts –
Answer
Light energy to electrical energy
941) The temperature of a body is an indicator of –
Answer
The average kinetic energy of the molecules of the body
942) Two stones of different masses are dropped simultaneously from the top of a building –
Answer
Both the stones reach the ground at the same time
943) Rainbow is due to -
Answer
refraction and reflection of sunlight by water droplets
944) Condensation process refers to :
Answer
Conversion of water vapour into its liquid form
945) If a band is played on the moon the sound will -
Answer
not be heard at any distance at all from it
946) In a water lifting electric pump, We convert –
Answer
Electrical energy into Potential energy
947) An electron microscope gives higher magnification than an optical microscope, because:
Answer
the wavelength of electrons is smaller as compared to the wavelength of visible light
948) We always see the same lace of the moon, because –
Answer
It takes equal time for revolution around the earth and rotation on its own axis
949) What is viewed through an electron microscope?
Answer
Structure of bacteria and viruses
950) Why does bleeding occur through the nose in high mountainous regions?
Answer
The blood pressure of a person increases at high altitudes
951) Pipelines in cold countries often burst in winter, because –
Answer
Water freezes and expands in its volume
952) The modulus of rigidity is the ratio of –
Answer
Shearing stress to shearing strain
953) In heating frozen foods in sealed pouches in microwaves, why do you first poke holes in the pouch?
Answer
To prevent the steam pressure from bursting open the pouch
954) A sphere rolls down on two inclined planes of different angles but same height, it does so –
Answer
with the same speed
955) During hot weather, the fan produces a feeling of comfort. This is because –
Answer
our perspiration evaporates rapidly
956) Stars appears to move from east to west because -
Answer
the earth rotates from west to east
957) An egg sinks in soft water but floats in a concentrated solution of salt because –
Answer
The density of salt solution exceeds the density of eggs
958) A hydrogen balloon floats because of –
Answer
Weight of the balloon is less than the weight of air displaced by it
959) The term ‘equinox’ means –
Answer
When the day and night are of equal duration
960) After long periods of use, a grey spot develops on the inside of a bulb. This is because –
Answer
dust inside the bulb condenses on the top
961) The blue colour of water in the sea is due to –
Answer
absorption of other colours except blue by water molecules
962) Why Earth is called the blue planet?
Answer
Because of two-thirds surface covered by water
963) The density of a gas is maximum at –
Answer
Low temperature, high pressure
964) A person standing on a railway platform listens to the whistles of arriving and departing trains. The whistle heard is -
Answer
of higher pitch when train arrives
965) The cause for the Tsunami, as deduced by the seismologists, is –
Answer
Deformation of sea floor and vertical displacement of water
966) Should cars have bumpers that collapse under impact?
Answer
Yes, since they help to absorb the impact of a collision and keep the occupants safe
967) Light houses are places with powerful lights to :
Answer
guide and warn the ships coming from different directions in the ocean.
968) A bird sitting on a high tension electric wire does not get electrocuted because –
Answer
it does not form a closed path for the flow of current
969) A vacuum cleaner works on the principle of pressure difference. On the moon it will –
Answer
not work at all
970) The propagation of sound waves in a gas involves –
Answer
Adiabatic compression and rarefaction
971) When a body is taken from earth to moon –
Answer
Weight changes but mass remains same
972) Superconductors are those elements –
Answer
Whose resistance falls almost to zero at very low temperature
973) Ail oil drop spreads over water because –
Answer
surface tension of oil is much smaller than that of water
974) The nature of fuse wire is –
Answer
high resistance and low melting point.
975) In a railway track, two rails are joined end to end with a gap in between them because –
Answer
accidents due to expansion in summer can be avoided.
976) When a pall of water is swung in a vertical circle, the water does not fall out at the top of the loop when the speed is –
Answer
above a certain minimum value irrespective of amount of water in the pail
977) Vehicle tyres are inflated properly –
Answer
to avoid skidding and to minimize friction
978) Refrigeration is a process which –
Answer
slows down the bacterial growth
979) The function of ball bearings in a wheel is –
Answer
to convert kinetic friction into rolling friction
980) A mirage occurs because of –
Answer
Total internal reflection by layers of air
981) Knot is a measure of –
Answer
The speed of ship
982) When the main switch of the house is put off it disconnects the –
Answer
live wire and the neutral wire
983) Negative feedback in amplifiers –
Answer
increases bandwidth and decreases noise
984) What is Hooke's Law?
Answer
Stress is directly proportional to strain.
985) Wollen clothes keep the body warm because –
Answer
Wool is a had conductor
986) Flywheel is an important part of a steam engine because it -
Answer
helps the engine in keeping the speed uniform
987) The bats can fly in the dark because –
Answer
They generate flashes of light
988) A microscope used in pathological laboratories forms –
Answer
Magnified, virtual and inverted image
989) It is dangerous to observe solar eclipse with naked eyes because –
Answer
Ultraviolet radiations from Sun burn our retina
990) The wall of a dam is broader at the base –
Answer
to withstand pressure that increases with depth
991) A transformer –
Answer
is used to decrease or increase AC voltage
992) 'Mirage' is an example of –
Answer
refraction and total internal reflection of light
993) The absolute zero is a temperature at which _.
Answer
molecular motion in a gas would cease
994) Surface tension in a liquid is due to :
Answer
Cohesive force between molecules
995) When a vehicle passes, TV reception gets distorted. This is because –
Answer
spark plug creates electromagnetic disturbances
996) The snow on the mountains does NOT melt all at once when it is heated by the sum because:
Answer
It reflects most of the heat from the sum
997) The water from a hand pump is warm in winter because -
Answer
the temperature inside the Earth is higher than the atmospheric temperature
998) ‘Mirage' is an example of -
Answer
refraction and total internal reflection of light
999) It is easier to carry two buckets of water in one hand each, than to carry only one in one hand because –
Answer
centre of gravity and centre of equilibrium fall within the feet
1000) If a band is played on the moon the sound will -
Answer
not be heard at any distance at all from it
1001) Dynamo is a device for converting –
Answer
Mechanical energy into electrical energy
1002) The magnifying power of an astronomical telescope can be decreased by –
Answer
increasing the focal length of the eyepiece
1003) The velocity of sound in air –
Answer
decreases with decrease of temperature
1004) The sensation of weightlessness in a spacecraft in an orbit is due to the –
Answer
Acceleration in the orbit which is equal to the acceleration due to gravity outside
1005) Energy in reflected light :
Answer
increases with the increase in angle
1006) A person standing on a railway platform listens to the whistles of arriving and departing trains. The whistle heard is –
Answer
of higher pitch when train arrives
1007) A dynamo is a device which –
Answer
converts mechanical energy into electrical energy
1008) Woollen cloth protects the body from cold because –
Answer
it is a poor conductor of heat
1009) The threshold frequency is the frequency below which -
Answer
photo electric emission is not possible
1010) Oil rises up the wick in a lamp because –
Answer
Of the capillary action phenomenon
1011) The velocity of sound in moist air is more than in dry air because the moist air has –
Answer
less density than city air
1012) The owl can see most clearly in total darkness because –
Answer
it has large eyes with orbs directed forward, giving it binocular sight
1013) Water boils at a lower temperature on the hills because –
Answer
there is a decrease in air pressure on the hills
1014) Bats can sense obstacles because they produce –
Answer
ultrasonic sound waves
1015) A satellite in vacuum -
Answer
does not require any energy for orbiting
1016) The sky appears blue because –
Answer
The atmosphere scatters blue colour more than the others
1017) Mercury is commonly used as a thermometric fluid rather than water because
Answer
mercury has greater visibility than water
1018) A barometer is kept inside a bell jar. Air is slowly pumped out of the jar.
Answer
The mercury level starts rising
1019) Melting point of ice _.
Answer
decreases with increase of pressure
1020) The threshold frequency is the frequency below which –
Answer
photo electric emission is not possible
1021) The blue colour of sky is due to –
Answer
scattering of shorter wave-lengths of sunlight in the atmosphere
1022) Metal tea pots have wooden handles because –
Answer
it prevents electric shock
1023) Flywheel is an important part of a steam engine because it –
Answer
helps the engine in keeping the speed uniform
1024) The rice is cooked more quickly in a pressure cooker because –
Answer
water boils at a higher temperature under pressure.
1025) Photophobia is -
Answer
the adjustment of the eye for light
1026) Where do the electrical charges reside in a charged conductor?
Answer
outer surface of the body
1027) On a cold day when the room temperature is 15°C, the metallic cap of a pen becomes much colder than its plastic body, though both are at the same temperature of 15°C, because –
Answer
metals are good conductors of heat
1028) The apparent weight of a person in a lift which is moving down with uniform acceleration is .
Answer
less than the weight when the person is stationary
1029) Air Quality Index is -
Answer
a measuring scale to show quality of air
1030) If we want to calculate the pressure of a liquid at the bottom of a vessel, the quantity which is not required to determine it, is –
Answer
Surface area of the bottom of the vessel
1031) It is easy to burst a gas-filled balloon with a needle than with a nail. It is because –
Answer
needle exerts more pressure than nail on the balloon.
1032) For a body floating in water, the apparent weight is equal to -
Answer
Weight of the body minus weight of the liquid
1033) The characteristic invalid for heat radiation is that it travels –
Answer
with the speed of light
1034) The method of magnetization is:
Answer
hammering a magnet
1035) Two vectors are said to be equal if –
Answer
both magnitude and direction are same
1036) A real gas can act as an ideal gas in -
Answer
low pressure and high temperature
1037) The Dynamo converts –
Answer
Mechanical Energy into Electrical Energy
1038) A Fuse wire is characterized by –
Answer
Low resistance and low melting point
1039) Ice is packed in saw dust because –
Answer
saw dust is poor conductor of heat.
1040) A stone is dropped from the roof of a house towards the ground. The kinetic energy of the stone will be maximum:
Answer
just before it touches the ground
1041) What is Hooke’s Law?
Answer
Stress is directly proportional to strain.
1042) Transfer of heat energy from a heater coil to the cooking vessel takes place through the process of-
Answer
Radiation and convection only
1043) A drop of liquid assumes spherical shape because:
Answer
A sphere has the least surface area for a given volume
1044) What are audible sound waves?
Answer
Having frequency between 20 Hz to 20000 Hz
1045) Sun appears red in colour at sun-rise and sunset due to –
Answer
that all other colours scatter away except red
1046) Why does a cannon recoil after firing?
Answer
NeMon's third law of motion
1047) During the motion of a projectile fired from the earth surface, .
Answer
horizontal component of its velocity remains constant
1048) A system exhibiting S.H.M. must possess –
Answer
Elasticity as well as inertia
1049) The ringing of an electric bell in an enclosed evacuated glass bell jar is not heard outside because -
Answer
there is no air or any other gas in the bell jar
1050) At hill stations, the boiling point of water will be –
Answer
less than that at sea level
1051) The information of brilliant colors in a thin soap film is a consequence of the phenomena of -
Answer
Multiple reflection and interference
1052) Indicate the correct arrangement for electromagnetic radiation in order of their increasing wavelength.
Answer
X-rays, infrared, visible, microwave
1053) A black body can absorb radiations of ;
Answer
all wavelengths
1054) The water from a hand pump is warm in winter because –
Answer
The temperature inside the earth is higher than the atmospheric temperature
1055) When hot liquid is poured into a thick glass tumbler, it cracks because glass –
Answer
is a bad conductor of heat so only inner surface expands
1056) Hydro-electric power is a:
Answer
renewable natural resource
1057) The electric motor converts -
Answer
Electrical energy into mechanical energy
1058) Burns caused by steam are much severe than those caused by boiling water because –
Answer
Steam has latent heat
1059) According to special theory of relativity the mass of a particle –
Answer
increases with increase in velocity with respect to an observer.
1060) Vegetables are cooked in lesser time by adding a pinch of salt while cooking because –
Answer
boiling point of water increases
1061) The wavelength at which the peak of intensity of blackbody radiation Occurs –
Answer
decreases with increase in temperature
1062) A dynamo converts .
Answer
Mechanical energy into electrical energy
1063) If we want to calculate the pressure of a liquid at the bottom of a vessel, the quantity which is not required to determine it, is –
Answer
Surface area of the bottom of the vessel
1064) The water from a hand pump is warm in winter because –
Answer
The temperature inside the earth is higher than the atmospheric temperature
1065) What is the relation between wavelength, frequency and velocity?
Answer
velocity of wave = frequency * wavelength
1066) Ozone layer in the outer atmosphere helps us in –
Answer
absorbing U-V radiations
1067) Stationary wave is formed by –
Answer
two waves of same frequency travelling in the opposite direction
1068) What is inertia?
Answer
Tendency to resist change in the current state
1069) A good conductor while carrying current is -
Answer
negatively charged
1070) The propagation of sound waves in a gas involves –
Answer
Adiabatic compression and rarefaction
1071) We always see the same lace of the moon, because –
Answer
It takes equal time for revolution around the earth and rotation on its own axis