Question

The total work done on a particle is equal to the charge in its kinetic energy

• A. always
• B. only if the forces acting on it are conservative
• C. only if gravitaional force alone on it
• D. only if elastic force alone acts on it

Answer 1

The correct option is B only if the forces acting on it are conservative

Work energy theorem $(W=\Delta K)$ holds true only when conservative force act on the system. As for a conservative force ($W=\overrightarrow{D},\Delta \overrightarrow{r})$ however in any non- conservative system, $W$ can be O but $AK>O$ (say eq: vertical circle system where gravity acts as non conservative).