NEET2002PhysicsElectrostaticsActual
Identical charges (-q) are placed at each corner of a cube of side ' b ' then the electrical potential energy of charge (+ q ) which is placed at the centre of cube will be:
Options
- A-4 2 q^2 ₀ b
- B-8 2 q^2 ₀ b
- C-4 q^2 3 ₀ b
- D8 2 q^2 4 ₀ b
Correct answer
C. -4 q^2 3 ₀ b
Step-by-step solution
Distance between the charge -q and +q is r= ( 2 b)^2+(b)^2 2 = 3 2 b Electric potential energy of charge aligned & +q is v=8 1 4 ₀ a(-a) r & =8 1 4 ₀ q(-a) 3 2 b & U= -4 q^2 3 ₀ b aligned