Question

Gauss law of gravitation is

• A. $ \oint{\mathbf{\vec{g}}.d\vec{s}=m} $
• B. $ \oint{\mathbf{\vec{g}}.d\vec{s}=Gm} $
• C. $ \oint{\mathbf{\vec{g}}.d\vec{s}=4G\pi m} $
• D. All of the above

Answer 1

Answer: (C)

The integral form of Gausss law for gravity state $ \oint_{\partial V}{g.ds=-4\pi Gm} $ where $ \partial V $ is any closed surface, ds is a vector whose magnitude is the area of an infinitesimals small piece of surface $ \partial V, $ and whose direction is the outward pointing surface normal, m is the total mass enclosed within the surface $ \partial V. $ The left hand side of this equation is called the flux of gravitational field. Flux of gravitational field is always negative (or zero) and never positive.