A) \[5\text{ }\mu F\]
B) \[7.5\text{ }\mu F\]
C) \[22.5\mu F\]
D) \[30\text{ }\mu F\]
Correct Answer: D
Solution :
Capacity of air capacitor \[C=\frac{A{{\varepsilon }_{0}}}{d}\] On placing a metallic plate of thickness t. \[C'=\frac{A{{\varepsilon }_{0}}}{d-t}\] \[\frac{C'}{C}=\frac{d}{d-t}\] \[\frac{C'}{15}=\frac{6}{6-3}\] \[C'=30\mu F\]You need to login to perform this action.
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