The unit of time period is :

1. Hertz
2. Nanometre
3. Second
4. Centimetre

The relationship between time period and frequency :

1. f = T
2. f = $\dfrac{1}{T}$
3. f = $\sqrt{T}$
4. None of these

The effective length of a pendulum is related with time period as :

1. T² ∝ l²
2. T³ ∝ l
3. T² ∝ l
4. T ∝ L³

A simple pendulum is made by suspending a bob of mass 1 kg by a string of length l. Now if the length of this pendulum is increased to 4l, then its time period T will :

1. remain the same
2. become twice
3. become four times
4. become half