Question

A pendulum clock is taken inside 1km from sea level its time period increases or decrease

Answer 1

Gravitational acceleration decreases with altitude. The time period of a simple pendulum varies inversely as the square root of the gravitational acceleration. Hence the pendulum's time period will increase. In other words, it will take more time to complete one cycle, and hence it will lose time.The time perod for simple pendulum is inversely proportional to the square root of acceleration due to gravity.
Time period=2×pie×(l/g)^0.5
And acceleration due to gravity is inversely related to square of the distance from the center of the earth.
g=GM/r^2
Thus, higher the altitude, lesser the acceleration due to gravity, and greater the time period.And it will lose time..