NEET Exam Model Paper 7

For a pendulum,T=2π√

1

g

where l is measured upto Centre of gravity. The centre of gravity of system is at Centre of sphere when hole is plugged. When unplugged, water drains out. Centre of gravity goes on descending. When the bob becomes empty, centre of gravity is restored to centre.
∴Length of pendulum first increases, then decreases to original value
∴T would first increase and then decrease to the original value