Question

Define gravitational constant g

Answer 1

The gravitational constant G is a key quantity in Newton's law of universal gravitation.

The gravitational constant (also known as the "universal gravitational constant", the "Newtonian constant of gravitation", or the "Cavendish gravitational constant"[1]), denoted by the letter G, is an empirical physical constant involved in the calculation of gravitational effects in Sir Isaac Newton's law of universal gravitation and in Albert Einstein's general theory of relativity.

In Newton's law, it is the proportionality constant connecting the gravitational force between two bodies with the product of their masses and the inverse square of their distance. In the Einstein field equations, it quantifies the relation between spacetime topology and energy–momentum.

The measured value of the constant is known with some certainty to four significant digits. In SI units its value is approximately 6.674×10−11 N·kg–2·m2.

The modern notation of Newton's law involving G was introduced in the 1890s by C. V. Boys. The first implicit measurement with an accuracy within about 1% is due to Henry Cavendish in a 1798 experiment.[2]

Answer 2

Heya mate
@Hirak here,

It is numerically equal to the force acting between two bodies of unit masses kept at a unit of each other. The value of "G" is same at every point of the earth surface. It never be Zero. It's value is 16 × 10 is to the power minus 11 Newton meter Square per kg Square.

Hope you satisfied with my answer...