Question

The 240 V air conditioning motor at a residence is rated at I hp with a power factor of 0.65 (lagging). Determine the equivalent (a) impedance and (b) admittance of the ac motor.

Answer 1

(a) 50.20 ohm (b)
`0.0199ohm^(-1)`

Step-by-step explanation:

e have given the power P =1 hp =745.7 W

Voltage V =240 V

Power factor
`cos\Phi =0.65`

We know that power
`P=Vicos\Phi`

So
`745.7=240* i* 0.65`

i =4.7801 A

Now according to ohm's law
`i=(V)/(Z)`

(a) So
`Z=(V)/(i)=(240)/(4.78)=50.20ohm`

(b) Admittance of any circuit is the inverse of the impedance

So admittance
`Y=(1)/(Z)=(1)/(50.20)=0.0199ohm^(-1)`