6. ⇒ (MHT CET 2023 9th May Morning Shift )
A rubber ball filled with water, having a small hole is used as the bob of a simple pendulum. The time period of such a pendulum
A. is a constant.
B. decreases with time.
C. increases with time.
D. first increases and then decreases, finally having same value as at the beginning.
Correct Option is (D)
From
The effective length increases due to this flow of water. Therefore, increases. As the water flows out, the length decreases and becomes equal to the original length. Hence, the time period becomes equal to the value at the beginning.
7. ⇒ (MHT CET 2021 21th September Evening Shift )
A pendulum clock is running fast. To correct its time, we should
A. reduce the mass of the bob.
B. reduce the amplitude of oscillation.
C. increase the length of the pendulum.
D. reduce the length of the pendulum.
Correct Option is (C)
The periodic time of a pendulum is given by
Hence, to increase the periodic time, length has to be increased. The periodic time is independent of mass and amplitude.