A series `R-C` circuit is connected to an alternating voltage source. Consider two situations
(a) When capacitor is air filled.
(b) When capacitor is mica filled.
current through resistor is `i` and voltage across capacitor is `V` then

Options

A. `V_(a) gt V_(b)`
B. `i_(a) gt i_(b)`
C. `V_(a) = V_(b)`
D. `V_(a) lt V_(b)`

Answer

A

Explanation

Voltage across capacitor
`V_(C) = i X_(C)`
`= (V)/(2) xx X_(C)`
`= (V)/(sqrt(R^(2) + C_(C)^(2))) xx (1)/(2 pi f C)`

`rArr V_(C) = (V)/(sqrt(R^(2) + 4 pi ^(2) f^(2) C^(2))) xx (1)/(2 pi f C)`
as mica is introduced, capacitance will increase, voltage across capacitor get decreases