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Physics · WORK, ENERGY AND POWER
हिन्दीGiven below are two statements: Statement I: When non-conservative forces act on a body, the total mechanical energy \( E = K + V \) is always conserved. Statement II: The work done by non-conservative forces is equal to the change in the total mechanical energy of the system, \( \Delta E = W_{nc} \). In the light of the above statements, choose the most appropriate answer from the options given below:
Correct answer · Option 4
Statement I is incorrect but Statement II is correct.
Explanation
When non-conservative forces act, mechanical energy is generally dissipated as heat/sound, so \( E \) is not conserved (Statement I is incorrect). The work-energy relation gives \( \Delta(K + V) = W_{nc} \), so Statement II is correct.
