NEET Physics Question - Capacitors - Spherical Capacitors

Assertion (A): When outer grounded shell of a two charged concentric shell system is removed, the capacitance of system decreases.

Reason (R): Electric field will spread in vast region till infinity.

Both (A) & (R) are true and the (R) is the correct explanation of the (A)

Both (A) & (R) are true but the (R) is not the correct explanation of the (A)

(A) is true but (R) is false

Both (A) and (R) are false

Solution:

For a concentric spherical capacitor, capacitance is \( C = \frac{4\pi\epsilon_0 ab}{b-a} \). When the outer shell (radius \( b \)) is removed, it becomes a single isolated sphere of radius \( a \), and its capacitance is \( C' = 4\pi\epsilon_0 a \). Since \( \frac{b}{b-a} > 1 \), \( C > C' \), so capacitance decreases. The electric field now extends to infinity, which explains the decrease in capacitance. Thus, (A) is true and (R) is a correct explanation.

Rankers Physics

Concentric Shell Capacitance

Solution:

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