Variation of g with Altitude and Depth

Yes, the value of g does change with altitude and depth. At higher altitudes, the value of g decreases because you are farther from the center of the Earth. Mathematically, it can be shown that g decreases with the square of the distance from the Earth's center. Conversely, as you go below the Earth's surface (depth), the value of g also decreases. This is because the effective mass of the Earth attracting the object reduces as you go deeper. The formula for g's variation with altitude and depth can be found in the NCERT textbook, but the key point is that g is not constant and varies depending on your position relative to the Earth's surface.