Important questions about Inductors. Inductors MCQ questions with answers. Inductors exam questions and answers for students and interviews.

1. When the current through an inductor decreases, the amount of energy stored in the electromagnetic field

Options

A : increases

B : decreases

C : remains the same

D : doubles

2. An inductor, a 1 k? resistor, and a switch are connected in series across a 6 V battery. At the instant the switch is closed, the inductor voltage is

Options

A : 0 V

B : 6 V

C : 12 V

D : 4 V

3. An inductor and a resistor are in series with a sine wave voltage source. The frequency is set so that the inductive reactance is equal to the resistance. If the frequency is increased, then

Options

A : V R ? V L

B : V L < V R

C : V L = V R

D : V L > V R

4. A 240 µH inductor is equivalent to a

Options

A : 0.240 mH inductor

B : 0.000240 mH inductor

C : 240 mH inductor

D : 240 H inductor

5. Five inductors are connected in series. The lowest value is 8 ?H. If the value of each inductor is twice that of the preceding one, and if the inductors are connected in order of ascending values, the total inductance is

Options

A : 8 H

B : 32 ?H

C : 64 ?H

D : 248 ?H

6. The winding resistance of a coil can be increased by

Options

A : increasing the number of turns

B : using a thinner wire

C : changing the core material

D : increasing the number of turns or using thinner wire

7. When the current through an inductor is cut in half, the amount of energy stored in the electromagnetic field

Options

A : is quartered

B : quadruples

C : doubles

D : does not change

8. An inductance of 0.43 mH is smaller than

Options

A : 43 µH

B : 430 µH

C : 0.05 H

D : 0.00043 H

9. A 2 mH, a 3.3 mH, and a 0.2 mH inductor are connected in series. The total inductance is

Options

A : 55 mH

B : less than 0.2 mH

C : less than 5.5 mH

D : 5.5 mH

10. The voltage across a coil when di/dt = 20 mA/µs and L = 8 µH is

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A : 16 mV

B : 160 mV

C : 1.6 mV

D : 2.5 mV

1. The current through a 120 mH coil is changing at a rate of 150 mA/s. The voltage induced across the coil is

Options

A : 1.8 mV

B : 18 mV

C : 180 mV

D : 1.25 mV

2. An inductance of 0.08 µH is larger than

Options

A : 0.0000008 H

B : 0.000000008 H

C : 0.000008 H

D : 0.00008 mH

3. An ohmmeter is connected across an inductor and the pointer indicates zero ohms. The inductor is

Options

A : good

B : open

C : shorted

D : partly shorted

4. Faraday's law states that relative motion between a magnetic field and a coil induces a voltage across the coil.

Options

A : True

B : False

C :

D :

5. An induced voltage is produced as a result of a dc voltage.

Options

A : True

B : False

C :

D :

6. Inductance is the property of an inductor that produces an opposition to any change in current.

Options

A : True

B : False

C :

D :

7. X L is directly proportional to frequency and inductance.

Options

A : True

B : False

C :

D :

8. Inductance is indirectly proportional to the square of the number of turns, the permeability, and the cross-sectional area of the core.

Options

A : True

B : False

C :

D :

9. The permeability of a core material is an indication of the ability of the material to establish a magnetic field.