Question

a coil has an inductance of 0.7H and is joined in series with the resistance of 220 ohm when the alternating EMF of 220 volt at 50 Hz is applied to it in the phase through which current lags behind the applied emf and the wattless component of current in the circuit will be respectively​

Answer 1

• first we calculate the impedance as
• $\sqrt{220 { + (2 \times 3.14 \times 50 \times 0.7)}^{2} }$
• that is equal to 220
• then we calculate the angle as inverse of tan XL divided by R
• that equals 45 degree
• Now we calculate Irms as Vrms
• $\frac{ \div }{?}$
• impedance which is 220
• the Irms value is 1
• power factor is calculated as Vrms x Irms cos (theta)
• this equals
• (220)(1)cos(45 degree)
• this equals 155 .5 watts

Answer 2

Please refer this

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