Question

If Uₑ = kQq/r, and Uᵍ = 12 Joules, and Q and q are doubled, what is the new value of Uₑ? (where k = 9.0 x 10^9 Nm^2/C^2)

a) 48 Joules
b) 24 Joules
c) 96 Joules
d) 12 Joules

Answer 1

The new value of Uₑ, when Q and q are doubled, is 48 Joules.

Step-by-step explanation:

The equation Uₑ = kQq/r represents the electric potential energy between two charges Q and q at a distance r apart. If Q and q are doubled, the new value of Uₑ can be calculated by substituting the new values into the equation.

Given: Uᵍ = 12 Joules, Q and q are doubled

Uₑ = k(Q x 2)(q x 2) / r = 4kQq / r

Therefore, the new value of Uₑ is 4 times the initial value, which is 4 x 12 = 48 Joules. So, the correct answer is option a) 48 Joules.