Question

If a torque of 1.25 Nm acts on a circular ring for 4 s, then its angular momentum changes by ($kgm^2s^{-1}$):

• A. 25
• B. 50
• C. 15
• D. 5
• E. 10

Hint:

Angular impulse (Torque $\times$ time) is equal to the change in angular momentum, similar to linear impulse ($F \times t = \Delta P$).

Answer 1

The Correct Option is D

Step 1: Concept
Torque $\tau = \frac{\Delta L}{\Delta t}$, so change in angular momentum $\Delta L = \tau \Delta t$.

Step 2: Analysis
Given $\tau = 1.25\ Nm$ and $\Delta t = 4\ s$.

Step 3: Calculation
$\Delta L = 1.25 \times 4 = 5\ kgm^2s^{-1}$. Final Answer: (D)