I've been presented with this question:
The coil is connected across a 360 V, 60 Hz supply and potential difference of 30 V is measured across a coil when a current of 3A flows through the coil. When an alternating current of 5A flows through the coil at 45 Hz, the potential difference is 210 V across the coil. calculate:
a) the total current,
b) the power dissipated, and
c) the power factor of circuit.
What I've done thus far is:
- calculated the current with the 45Hz source
- gotten XL with the 45Hz source
- calculated the inductance for the 45Hz source
- used the ratio of the frequencies to calculate XL and Z for the 60Hz source
- calculated the current
- used the current and previously calculated XL to get the power
- used Z to calculate VA power and then got the power factor
My final answers are I = 6.53 A; P = 426.51 W and PF = 0.18.
I'm pretty sure that what I've done is incorrect. Could anyone assist? Should the values have a complex notation?
