When a negative charge is moved from surface of Earth to a certain height, its gravitational potential energy ...... .

Options

A. remains constant
B. increases
C. decreases
D. would become infinite

Answer

A, C

Explanation

At the surface of Earth
`U_(1) = -(GMm)/(R)`
( Where m = mass of given negative charge )
At height h above surface of Earth
`U_(2)=-(GMm)/(R+h)`
`:. U_(2)-U_(1)=-(GMm)/(R+h)-((-GMm)/(R))`
`:. U_(2)-U_(1)=GMm((1)/(R)-(1)/(R+h))`
Here `R lt R +himplies (1)/(R) gt (1)/(R+h)`
`:. U_(2)-U_(1)gt 0`
`:. U_(2) gt U_(1)`
Gravitational potential energy increases as we move away from surface of Earth.