What is the period of a pendulum?

a)the length of the string
b)the height to which the pendulum is first pulled back
c)the number of times the pendulum can swing back and forth in one minute
d)the time it takes for the bob to swing back and forth once

d)the time it takes for the bob to swing back and forth once

Explanation:

Time period of any object is defined as the time after which it can complete its one round of repetitive motion

So here in the back and forth motion of simple pendulum we know that it will move to and fro about its mean position and the total time to make its to and from motion is known as its time period

so here correct answer would be

d) the time it takes for the bob to swing back and forth once

for simple pendulum the formula of time period is given as

here we know

L = length of pendulum

g = acceleration due to gravity

the answer is a. hope this .