Physics
State the energy conversions taking place:
(a) during photosynthesis
(b) in a thermocouple
(c) during bursting a cracker
Work, Energy & Power
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Answer
(a) Light energy → Chemical energy
Reason : During photosynthesis, the light energy from the Sun is absorbed by the green plants and they change it in the form of chemical energy (food).
(b) Heat energy → Electrical energy
Reason : In a thermocouple, when two junctions of two different metals are kept at different temperatures (one junction is kept hot, while the other cold), a current flows in the thermocouple. Thus, a thermocouple changes the heat energy supplied at the hot junction into electrical energy.
(c) Chemical energy → Heat energy + light energy + sound energy
Reason : In a cracker different chemicals in the presence of heat react with each other and it's stored chemical energy is rapidly released as heat, light, and sound.
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