OnlineCBT
Physics · WORK, ENERGY AND POWER
हिन्दीGiven below are two statements regarding power: Statement I: Instantaneous power can be expressed as the scalar product of force vector and instantaneous velocity vector, \( P = \mathbf{F} \cdot \mathbf{v} \). Statement II: Power is a vector quantity having dimensions \( [\text{M L}^2 \text{T}^{-3}] \). In the light of the above statements, choose the most appropriate answer from the options given below:
Correct answer · Option 3
Statement I is correct but Statement II is incorrect.
Explanation
Statement I is correct since \( P = \frac{dW}{dt} = \mathbf{F} \cdot \frac{d\mathbf{r}}{dt} = \mathbf{F} \cdot \mathbf{v} \). Statement II is incorrect because power is a scalar quantity, even though its dimensions are indeed \( [\text{M L}^2 \text{T}^{-3}] \).
