Question

The frequency of voltage source used in ac circuit is 5 kHz. The circuit contains a coil of inductance of 0.5 mH, a capacitor of capacitance of `10muF` and resistor of resistance 8 `Omega` are connected in series with source. The impedance of circuit is
A. `14.9Omega`
B. `1.49Omega`
C. `1.49Omega`
D. `18.9Omega`

Answer 1

Correct Answer - A
`X_(L)=2pifL`
`=2xx3.14xx5xx10^(3)xx0.5xx10^(-3)`
`=15.7Omega`
`X_(C)=(1)/(2pifC)=(1)/(2xx3.14xx5xx10^(3)xx10xx10^(-6))`
`=3.185Omega`
`Z=sqrt(R^(2)(X_(L)-X_(C))^(2))`
`=sqrt(64+(15.7-3.2)^(2))=14.84Omega`