GK INFOPEDIA

[1] Electric current in a metal wire is due to the flow of — A. Electrons B. Protons C. Ions D. Holes Ans: Electrons Explanation : A solid conductive metal contains mobile, or free electrons, originating in the conduction electrons. When a metal wire is connected across the two terminals of a DC voltage source […]

[1] Intensity of any wave is proportional to which of the following? A. Amplitude B. Square of amplitude C. Square root of amplitude D. Cube of amplitude Ans: Square of amplitude Explanation : The energy of a wave is proportional to the square of its amplitude. Therefore, the intensity of a wave is also proportional […]

[1] Supercooling is cooling of liquid _. A. below melting point B. below freezing point C. at melting point D. above melting point Ans: below freezing point Explanation : Supercooling, also known as undercooling, is the process of lowering the temperature of a liquid or a gas below its freezing point without it becoming a […]

[1] The frequency of direct current is . A. Zero B. 50 HZ C. 60 HZ D. 100 HZ Ans: Zero Explanation : Direct Current (DC) refers to power systems that use only one polarity of voltage or current, and to refer to the constant, zero-frequency, or slowly varying local mean value of a voltage […]

[1] Conversion of chemical energy into electrical energy occurs in – A. atomic bombs B. dynamo C. a battery D. electric heaters Ans: a battery Explanation : A battery is a form of chemical energy that can be converted to electrical energy. it is a device consisting of one or more electrochemical cells which performs […]

[1] Which one of the following non-metals is not a poor conductor of electricity? A. Sulphur B. Selenium C. Bromine D. Phosphorus Ans: Selenium Explanation : Selenium is a non-metallic element; it is not a very good conductor of heat and electricity. [2] Which instrument is used to record Atmospheric pressure? A. Thermometer B. Barometer […]

[1] What does the symbol R in electricity stand for? A. Refraction B. Resonance C. Rarefaction D. Resistance Ans: Resistance Explanation : In electricity, R stands for resistance, the property of an electric circuit or part of a circuit that transforms electric energy into heat energy in opposing electric current. [2] The velocity of light […]

[1] Convex mirrors are used as a rear view mirror in motor cycles because A. it forms real image B. it forms erect (upright) image C. it forms smaller image as compared with object D. All of the above Ans: it forms smaller image as compared with object Explanation : It is because image formed […]

[1] The device which converts AC to DC is – A. Oscillator B. Amplifier C. Rectifier D. None of these Ans: Rectifier Explanation : A rectifier is an electrical device that converts alternating current (AC), which periodically reverses direction, to direct current (DC), which flows in only one direction. The process is known as rectification. […]

[1] Longitudinal waves and Transverse waves are types of – A. Mechanical waves B. Non-Mechanical waves C. Both of above D. None of Above Ans: Mechanical waves Explanation : Mechanical Waves are waves which propagate through a material medium (solid, liquid, or gas) at a wave speed which depends on the elastic and inertial properties […]