Question

A table fan rotating at a speed of 2400 rpm is switched off and the resulting variation of revolution per minute with time is shown in figure. The total number of revolutions of the fan before it comes to rest is

• A. 160
• B. 380
• C. 420
• D. 480

Hint:

In cases involving rotational motion, the total distance (or revolutions) can be calculated using the area under the speed-time graph.

Answer 1

The Correct Option is B

Step 1: Understanding the relationship between speed and time.
By observing the graph and calculating the area under the curve, we can determine the total number of revolutions. The area under the graph gives us the total revolutions, which is 380.

Step 2: Conclusion.
The total number of revolutions before the fan comes to rest is 380, which corresponds to option (2).