Will a pendulum clock gain or lose time when it taken to the top of a mountain?

QUESTION:

Will a pendulum clock gain or lose time when taken to the top of a mountain?

Answer:

On the mountains acceleration due to gravity (g) is less as compared on the surface of earth(acceleration due to gravity decreases as we are going to certain height or depth from the surface of the earth). Since time period(T) is inversely proportional to the square root of the acceleration due to gravity(g), the time period increases. So the pendulum clock takes more time to oscillate i.e. loses time on the top of a mountain.