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Two coils A and B are connected in serie...

Two coils `A` and `B` are connected in series across a `240V ,50 `Hz supply The resistance of A is `5Omega` and the inductance of `B` is 0.02 H The power factor is `0.75` The impedance of the circuit is (if power consumed is 3kW) .

A

`0.144Omega`

B

`1.44Omega`

C

`14.4Omega`

D

`144Omega`

Text Solution

Verified by Experts

The correct Answer is:
C
`overline(P)=e_(rms)I_(rms)cosphi`
`=e_(rms)(e_(rms))/(Z)cosphi`
`therefore Z=(e_(rms)e_(rms)cosphi)/(overline(P))`
`=(240xx240xx0.75)/(3xx10^(3))`
`=14.4Omega`
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