Q.

Given below are two statements. One is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A) : A simple pendulum is taken to a planet of mass and radius, 4 times and 2 times, respectively, than the Earth. The time period of the pendulum remains same on earth and the planet.

Reasosn (R) : The mass of the pendulum remains unchanged at Earth and the other planet.

In the light of the above statements, choose the correct answer from the options given below:          [2025]

1 Both (A) and (R) are true but (R) is NOT the correct explanation of (A).  
2 (A) is true but (R) is false.  
3 (A) is false but (R) is true.  
4 Both (A) and (R) are true and (R) is the correct explanation of (A).  

Ans.

(1)

g=GMR2

g'=G(4M)(2R)2=g

A is correct, R is correct; but since T=2πlg

Doesn't depend on mass; R doesn't explain A.