7-103. When the inductance decreases, the end result is that the power in the load (true

power) increases. The following formulas show how each is affected by a decrease in

inductance.

XL = 2π fL

(inductive reactance in the circuit)

(impedance in the circuit)

Z=

2

2

E

I=

(current in the circuit)

Z

True power = I2R (true power or power in the load)

I increases. Finally, as I increases, true power increases. This general conclusion can be

confirmed by using some actual values of inductance in the formulas along with other

values from Figure 7-26.

7-104. If the value of inductance is 23 millihenries, the formulas yield the following

values:

XL = 2π fL

XL = (2)
(3.14) (60 Hz) (23 mH)

XL = 8.67 Ω (rounded
off)

Z=

XL2 + R 2

Z = (8.67 Ω 2 + (5 Ω) 2

Z = 100.1689 Ω

Z = 10 Ω (rounded off)

E

I=

Z

100 V

I=

10 Ω

I = 10 A

TruePower = I 2 R

True Power = (10A)2 x (5Ω5

True Power = 500 watts

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