A coil has an inductance of 0.7 H and is...

A coil has an inductance of `0.7 H` and is joined in series with a resistance of `220 Omega`. When an alternating e.m.f of `220 V` at 50 c.p.s. is applied to it, then the wattless component of the current in the circuit is

0.7A

0.5A

Text Solution

Verified by Experts

The correct Answer is:

Here, `X_L = 2pi v L = 2pi xx 50 xx 0.7 = 220 Omega, R = 220 Omega`
`Z = sqrt(R^2 + X_L^2) = sqrt(220^2 + 220^2) = 220 sqrt2 Omega`
`I_(rms) = (V_(rms))/(Z) = (220V)/(220sqrt2 Omega) = (1)/(sqrt2) A`
`sin phi = (X_L)/(Z) = (220)/(220 sqrt2) = (1)/(sqrt2)`
Wattless current ` = I_(rms) sin phi = (1)/(sqrt2) xx (1)/(sqrt2) = 1/2 A = 0.5 A`

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A coil has an inductance of 22/pi H and is joined in series with a resistance of 220 Omega .When an alternating e.m.f of 220 V at 50 c.p.s is applied to it.then the wattless component of the rms current in the circuit is

`5` ampere

`0.5` ampere

`0.7` ampere

`7` ampere

A coil has a iductance of 0.7H and is joined in series with a resistance of 220 Omega . When an alternating emf of 220V at 50 cps is applied to it, then the wattless component of the current in the circuit is (take 0.7 = 2.2)

0.5A

0.7A

A coll has an inductance of (2.2)/(pi)H and is joined m series with a resistance of 220Omega . When an alternating e.m.f. of 220 V at 50 c.p.s. is applied to it, then the wattless component of the runs current in the circuit is

5ampere

0.5ampere

0.7ampere

7ampere