Question

Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R
Assertion (A) : A ball connected to a string is in circular motion on a frictionless horizontal table and is in equilibrium.

Reason (R): Magnitude of the centripetal force is equal to the magnitude of the tension in the string.

In the light of the above statements, choose the correct answer from the options given below

• A. Both (A) and (R) are true and (R) is the correct explanation of .
• B. Both (A) and (R) are true but (R) is not the correct explanation of .
• C. (A) is true but (R) is not true.
• D. (A) is not true but (R) is true.

Answer 1

Answer: (B)

Both (A) and (R) are true but (R) is not the correct explanation of .

Answer 2

In a circular motion, the direction of resultant force is towards centre and its magnitude is $F=\frac{m{{v}^{2}}}{r}$ or $F=mr{{\omega }^{2}}$ Thus, a centripetal force of magnitude $\frac{m{{v}^{2}}}{r}$ is needed to keep the particle moving in a circle with constant speed.