Question

Why is ‘invar’ used for making the pendulum of a clock?

Answer 1

because the mass of invar are hevy that's way the invar are use to make the pendulum of clocks

Answer 2

Hey.

Here is your answer.

Invar is an alloy which has a small coefficient of linear expansion. The length of a pendulum made of invar does not change with temperature and hence the time period of oscillation remains the same. Hence the time shown by the clock is accurate.
That's why ‘invar’ is used for making the pendulum of a clock.

Thanks