JEE Advanced2009PhysicsElectrostaticsActual
A disk of radius a 4 having a uniformly distributed charge 6 C is placed in the x-y plane with its centre at ( -a 2 , 0,0 ) . A rod of length a carrying a uniformly distributed charge 8 C is placed on the x -axis from x= a 4 to x= 5 a 4 . Two point charges -7 C and 3 C are placed at ( a 4 , -a 4 , 0 ) and ( -3 a 4 , 3 a 4 , 0 ) , respectively. Consider a cubical surface formed by six surfaces x= a 2 , y= a 2 , z= a 2
Options
- A-2 C ₀
- B2 C ₀
- C10 C ₀
- D12 C ₀
Correct answer
A. -2 C ₀
Step-by-step solution
Total enclosed charge as already shown is q_ net = 6 C 2 + 8 C 4 -7 C=-2 C From Gauss-theorem, net flux, _ net = q_ net ₀ = -2 C ₀