31) The energy stored in a stretched spring is
(A) Potential energy
(B) Kinetic energy
(C) Heat energy
(D) Elastic potential energy
32) In cells chemical energy is transformed into
(A) Kinetic energy
(B) Potential energy
(C) Heat energy
(D) Electrical energy
33) When a body is dropped from a certain height, the gravitational potential energy is converted into
(A) Elastic potential energy
(B) Chemical energy
(C) Kinetic energy
(D) Light energy
34) Human body converts chemical potential energy of food into
(A) Kinetic energy
(B) Light energy
(C) Nuclear energy
(D) Heat energy
35) Electrochemical energy is required for the working of
(A) Circulatory system
(B) Nervous system
(C) Excretory system
(D) Digestive system
36) When the cat leaps for its prey then the chemical energy present in its muscles is converted to
(A) Potential energy then to light energy
(B) Potential energy then to kinetic energy
(C) Electrical energy then to heat energy
(D) Heat energy then to Nuclear energy
37) The energy stored in the fossil fuel is
(A) Chemical energy
(B) Heat energy
(C) Electrical energy
(D) Elastic potential energy
38) Semi conductor is such a substance whose ability to conduct current lies in between
(A) Conductors and insulators
(B) Conductors and superconductors
(C) Insulators and superconductors
(D) Wood and plastic
39) Though the temperature inside lighted electric bulb is around 2700°C, the filament does not burn because:
(A) The metal of which it is made is resistant to burning
(B) The oxygen necessary for combustion (and burning) is not available as the bulb is evacuated and filled with pure nitrogen or inert gases
(C) It does not burn in closed systems
(D) It is made of non-metallic substance
40) A remote control gadget (for TV etc) has in it
(A) A small electromagnet, that emits electromagnetic
(B) A small oscillator that emits electric pulses
(C) A small transmitter that emits infrared signals
(D) None of these