JEE MainPhysicsAlternating Current
A parallel plate capacitor consists of two circular plates of radius R . The electric field between the plates varies with time t as E = E₀ ( t) . The RMS value of the conduction current in the connecting wires is :
Options
- A₀ E₀ R^2
- B₀ E₀ R^2 2
- C2 ₀ E₀ R^2
- D2 ₀ E₀ R
Correct answer
B. ₀ E₀ R^2 2
Step-by-step solution
The electric flux _E between the capacitor plates is the product of the electric field and the area of the plates: _E = E A = E₀ ( t) R^2 The displacement current I_d is defined as: I_d = ₀ d _E dt Substituting the expression for electric flux: I_d = ₀ R^2 d dt (E₀ ( t)) I_d = ₀ E₀ R^2 ( t) The peak value of the displacement current is the amplitude of this sinusoidal function: I₀ = ₀ E₀ R^2 By Maxwell's equations, the conduction current in the connecting wires is equal to the displacement current in the capacitor.