Who founded the value of 'G'?

Henry Cavendish

The correct answer is option 1. Henry Cavendish.

The scientist who founded the value of 'G' is Henry Cavendish.

Henry Cavendish, an English physicist and chemist, is credited with determining the gravitational constant (commonly denoted as 'G') in 1798 through his famous Cavendish experiment. This experiment allowed Cavendish to measure the force of gravity between two masses and thereby determine the value of the gravitational constant. Cavendish's work laid the foundation for understanding the force of gravity and its role in the laws of physics.