Question

In the circuit shown in figureure the `AC` source gives a voltage `V=20cos(2000t)`. Neglecting source resistance, the voltmeter and and ammeter readings will be
.
A. 0 V, 0.47 A
B. 1.68 V, 0.47 A
C. 0 V, 1.4 A
D. 5.6 V, 1.4 A

Answer 1

Correct Answer - C::D
Z = `sqrt ((R)^(2) + (X_L - X_C)^(2))`
R = `10Omega`, `X_L` = `omega`L = `2000 xx 5 xx 10^(-3)` = `10Omega`
`X_C` = `1/omega`C = `1 / 2000 xx 50 xx 10^(-6)` = 10` Omega` i.e., Z = 10`Omega`
Maximum current, `i_o` = `V_o`/Z = 20 / 10 = 2A
Hence, `i_rms` = 2/`sqrt 2`= 1.4A
and `V_rms` = `4 xx 141` = 5.64V