NTA Abhyas JEE Main2020PhysicsElectrostaticsPractice
A hollow cylinder has a charge q placed at its centre. If ϕ is the electric flux (in V m ) associated with the curved surface B, the flux linked with the plane surface A is
Options
- A1 2 q ε 0 - ϕ
- Bq 2 ε 0
- Cϕ 3
- Dq ε 0 - ϕ
Correct answer
A. 1 2 q ε 0 - ϕ
Step-by-step solution
According to Gauss law, ϕ t o t a l = q ε 0 Let electric flux linked with surfaces A , B a n d C are ϕ A , ϕ B and ϕ C respectively. That is ϕ t o t a l = ϕ A + ϕ B + ϕ C Since ϕ C = ϕ A ∴ 2 ϕ A + ϕ B = ϕ t o t a l = q ε 0 o r ϕ A = 1 2 q ε 0 - ϕ B B u t ϕ B = ϕ g i v e n Hence, ϕ A = 1 2 q ε 0 - ϕ