Worksheet 14-Inductive Reactance

Question 1

How is inductive reactance in a series circuit calculated? What is the formula?

Answer 1

Total inductive reactance in a series circuit equals the sum of individual inductive reactances of the components in series.

X_LT=X_L1+X_L2+X_L3+…..X_Ln

Question 2

When given a circuit with values of inductors and the frequency of the input, how would you determine the circuit’s total reactance?

Answer 2

First, determine the X_L for each inductor and then solve for total reactance X_LT.

Question 3

Refer to the circuit and solve for total reactance (X_LT).

Answer 3

X_L1=2∏fL

X_L1=6.28 x 120Hz x 0.02H

X_L1=15Ω

X_L2=2∏fL

X_L2=6.28 x 120Hz x 0.04H

X_L2=30.1Ω

First solve for X_L then solve for total X_L in the circuit.

X_LT=X_L1+X_L2

X_LT=15Ω+30.1Ω

X_LT=45.1Ω

An easier method would be to add the inductors in series (0.02+0.04) to get the total circuit inductance and then calculate inductive reactance once.

Question 4

Refer to the circuit and solve for total reactance (X_LT).

Answer 4

X_L1=2∏fL

X_L1=6.28 x 400Hz x 360H

X_L1=904.3kΩ

X_L2=2∏fL

X_L2=6.28 x 400Hz x 480H

X_L2=1.2MΩ

First solve for X_L then solve for total X_L in the circuit.

X_LT=X_L1+X_L2

X_LT=904,320Ω+1,205,760Ω

X_LT=2,110,080Ω

An easier method would be to add the inductors in series (360H+480H) to get the total circuit inductance and then calculate inductive reactance once.

Question 5

How is total inductive reactance (X_LT) calculated in a parallel circuit?

Answer 5

Total inductive reactance in a parallel circuit is computed using the same methods as resistance in any parallel circuit.

Question 6

Referring to this circuit, calculate X_LT.

Answer 6

20Ω x 40Ω / 20Ω + 40Ω = 13.33Ω

25Ω x 15Ω / 25Ω + 15Ω = 9.37Ω

13.33Ω x 9.37Ω / 13.33Ω + 9.37Ω = 5.5Ω

X_LT = 5.5Ω

Question 7

What is Mutual Inductance.

Answer 7

Mutual inductance is where voltage can be induced by a primary coil into a separate secondary coil when the two coils are positioned closely enough so the secondary coil is cut by the primary coil’s magnetic flux lines.

Question 8

What are the two parts of a coil called in the Mutual Induction process?

Answer 8

Mutual Inductance occurs between the primary coil that conducts voltage into the secondary coil.

Question 9

Is current and voltage always in phase between the primary and the secondary?

Answer 9

Because of the delay in the buildup in the coils of the inductor, current will always be out of phase with the input that will then further adjust the phase in the secondary.