What effect occurs on the frequency of a pendulum if it is taken from the earth's surface to deep into a mine?

Given below are two statements: One is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: If we move from poles to equator,the direction of acceleration due to gravity of earth always points towards the center of earth without any variation in its magnitude.
Reason $R$: At equator,the direction of acceleration due to the gravity is towards the center of earth. In the light of above statements,choose the correct answer from the options given below.

The length of a seconds pendulum at a height $h=2R$ from the earth's surface will be. (Given: $R =$ radius of earth and acceleration due to gravity at the surface of earth $g = \pi^{2} \ m/s^{2}$)

How does the acceleration due to gravity $(g)$ at a location on Earth change with latitude?

As we move above the surface of the Earth,the value of acceleration due to gravity $g$ . . . . . . .

$A$ spherical part of radius $R/2$ is excavated from an asteroid of mass $M$ and radius $R$ as shown in the figure. The gravitational acceleration at a point on the surface of the asteroid just above the excavation is