Question

the tension in the wire of a pendulum when it is taken on the centre of the earth is how much

Answer 1

Explanation:

The potential energy is gravitational; gravity pulls it "down". On Earth "down" is "toward the center (of mass) of Earth". Therefore at the center of the Earth there is no "down", so the pendulum will not oscillate as at the surface. ... Because there is no net gravity working on the pendulum it is weightless.