Question

In a vertical circle of radius r, at what point in its path does a particle have tension equal to zero if it is just able to complete the vertical circle?

• A. Lowest point
• B. Highest point
• C. Horizontal point
• D. Any point

Hint:

At the highest point in the vertical circle, the tension in the string is minimal, and it is zero when the particle is just able to complete the circle.

Answer 1

The Correct Option is B

At the apex of the vertical circle, gravity acts downwards. The tension in the string also contributes to the centripetal force needed for circular motion. If the particle can just complete the circle, the string tension is zero at this point. This occurs because gravity alone supplies the required centripetal force.