AIIMS2018PhysicsCapacitance
Assertion : The force between the plates of a parallel plate capacitor is proportional to charge on it. Reason : Electric force is equal to charge per unit area.
Options
- AIf both assertion and reason are true and reason is the correct explanation of assertion.
- BIf both assertion and reason are true but reason is not the correct explanation of assertion.
- CIf assertion is true but reason is false.
- DIf both assertion and reason are false.
Correct answer
D. If both assertion and reason are false.
Step-by-step solution
The potential energy stored between the plates of capacitor, U= 1 2 Q^2 C = 1 2 Q^2 ₀ A x ( C= ₀ A x ) Force F= - U x =- x ( 1 2 Q^2 x ₀ A )=- 1 2 Q^2 ₀ A Negative sign shows force is attractive.