Deck 16: Rl Circuits

Question 1

Given the circuit in Figure 16-3, what is the voltage rms) across the inductor?

A) 4 V
B) 7.07 V
C) 10 V
D) 6 V

Answer 1

6 V

Question 2

In the circuit in Figure 16-1, assume that XL, = R. The phase angle is 45°.

Answer 2

True

Question 3

In a series RL circuit, the resultant voltage vector represents the total applied voltage.

Answer 3

True

Question 4

In the circuit in Figure 16-1, increasing the frequency will cause an increase in circuit current.

Question 5

Given the circuit in Figure 16-3, what is the voltage rms) across the resistor?

A) 4 V
B) 7.07 V
C) 3 V
D) 8 V

Question 6

In the circuit in Figure 16-2, the current through the inductor equals the current through the resistor.

Question 7

For parallel ac circuits containing resistance and inductive reactance, total current can only be found using right-triangle methods.

Question 8

In the circuit in Figure 16-1, increasing the frequency will cause an increase in circuit impedance.

Question 9

For series AC circuits containing both resistance and inductive reactance, total opposition to current flow cannot be found by simply adding ohmic values or oppositions to current.

Question 10

Given the circuit in Figure , what is the total circuit impedence Z?

A) 2.65 kΩ
B) 7 kΩ
C) 5.0 kΩ
D) 500 Ω

Question 11

In the circuit in Figure 16-1, The current lags the voltage.

Question 12

Phase angle is the difference in phase between the applied voltage and the circuit current.

Question 13

In the circuit in Figure 16-2, increasing the inductance value will cause an increase in circuit current.

Question 14

For voltage-current vector diagrams relating to series RL circuits, current is the reference vector because it is the same throughout the circuit.

Question 15

Given the circuit in Figure 16-3, what is the total circuit current?

A) 7.07 mA
B) 2.0 mA
C) 20 mA
D) 100 mA

Question 16

In the circuit in Figure 16-1, increasing the inductance value will cause an increase in circuit current.

Question 17

In the circuit in Figure 16-2, increasing the frequency will cause an increase in circuit current.

Question 18

In the circuit in Figure 16-2, assume that XL = R. The phase angle is 45°.

Question 19

In the circuit in Figure 16-2, increasing the frequency will cause an increase in circuit impedence.

Question 20

What is the total circuit impedance in Figure ?

A) 141.5 Ω
B) 195 Ω
C) 14.15 Ω
D) 120 Ω

Question 21

Given the circuit in Figure , what is the total circuit impedance?

A) 44.96 Ω
B) 449.6 Ω
C) 222.6 Ω
D) 268.3 Ω

Question 22

Given the circuit in Figure 16-5, what is the current through the inductor?

A) 1.0 A
B) 2.0 A
C) 3.0 A
D) 0.707 A

Question 23

In a series resistor/inductor circuit:

A) the same current flows through both the resistor and the inductor.
B) the resistor voltage is in phase with the current.
C) the inductor voltage leads the current by 90 degrees.
D) All of the above are correct.

Question 24

Given the circuit in Figure 16-6, what is the current through the resistor?

A) 21.8 mA
B) 1100 mA
C) 45.3 mA
D) 207.5 mA

Question 25

Given the circuit in Figure 16-6, what is the current through the inductor?

A) 533.3 mA
B) 300 mA
C) 21.8 mA
D) 218 mA

Question 26

Given the circuit in Figure 16-6, what is the impedance phase angle?

A) 87.6°
B) 45°
C) 23.4°
D) 43.2°

Question 27

Given the circuit in Figure 16-6, does the total current lead or lag the total voltage?

A) The total current IT) lags the total voltage VS).
B) The total current IT) leads the total voltage VS).

Question 28

The impedance of a series resistor/inductor circuit is defined as: 56 Ω + j75 Ω. What is the resistance value?

A) 93.6 Ω
B) 56 Ω
C) 75 Ω
D) 19 Ω

Question 29

Given the circuit in Figure 16-5, what is the total circuit current?

A) 5 A
B) 3 A
C) 4.69 mA
D) 2.24 A

Question 30

In a series RL circuit, if resistance increases, impedance will:

A) increase
B) drop to zero
C) decrease
D) remain the same.

Question 31

What is the Impedance of the circuit in Figure , expressed in rectangular form?

A) 75 Ω + j120 Ω
B) 141 Ω + j120 Ω
C) 120 Ω + j75 Ω
D) j75 Ω + j120 Ω

Question 32

Given the circuit in Figure , what is the total circuit impedance?

A) 569 Ω
B) 26.8 Ω
C) 268 Ω
D) 22.6 Ω

Question 33

Given the circuit in Figure 16-5, what is the current through the resistor?

A) 3.0 A
B) 0.707 A
C) 2.0 A
D) 1.0 A

Question 34

A 12 mH inductor is used in a circuit with a 10 kHz source. What is the inductive reactance?

A) 500 ohms
B) 754 ohms
C) 127 ohms
D) 1.33 k ohms

Question 35

If XL = 100 ohms and R = 100 ohms in a series RL circuit, then impedance will be:

A) 200 Ω
B) 14.14 Ω
C) 100 Ω
D) 141.4 Ω

Question 36

What is the Impedance of the circuit in Figure , expressed in polar form?

A) 120 32° Ω
B) 120 11ec81bf_ec6d_acdc_bc38_29a3f7414e20_TB34225555_11 -58° Ω
C) 141.5 11ec81bf_ec6d_acdc_bc38_29a3f7414e20_TB34225555_11 -58° Ω
D) 141.5 11ec81bf_ec6d_acdc_bc38_29a3f7414e20_TB34225555_11 58° Ω

Question 37

What is the phase angle of the circuit in Figure 16-4?

A) 32°
B) -32°
C) 58°
D) -58°

Question 38

A circuit has an apparent power of 240 VA, and a power factor of 0.943. What is the true power dissipated by the circuit?

A) 13.6 W
B) 226 W
C) 84.5 W
D) 240 W

Question 39

Given the circuit in Figure 16-6, what is the total circuit current?

A) 57.7 mA
B) 555.1 mA
C) 4.69 mA
D) 533.8 mA

Question 40

In a series RL circuit where R = 100 Ω and XL = 50 Ω, which of the following combinations is equivalent to the given series circuit?

A) R = 40 Ω in parallel with XL = 20 Ω
B) R = 125 Ω in parallel with XL = 250 Ω
C) R = 250 Ω in parallel with XL = 125 Ω
D) R = 20 Ω in parallel with XL = 40 Ω

Question 41

The total opposition that a series or parallel RL circuit offers to current flow is called .

A) inductive impedance
B) susceptance
C) reactance
D) impedance

Question 42

Figure 16-7
In Figure 16-7, the plot of the sine wave could represent the and the cosine wave could represent the
Relationship in a purely inductive circuit

A) current, voltage
B) current, impedance
C) voltage, current
D) voltage, impedance

Question 43

Figure 16-8
In Figure 16-8, for the voltage across the resistor to equal the voltage across the inductor:

A) XL must be smaller than R
B) XL must equal R.
C) XL must be larger than R
D) impedance must be zero.

Question 44

Switching power supplies:

A) are efficient at converting ac to dc
B) contain pulse-width modulators
C) can change unregulated dc to high frequency pulses
D) all of the above

Question 45

Resistance and inductive reactance must be added in a series RL circuit.

A) using vectors, or Pythagorean Theorem
B) inductively
C) using Kirchhoff's Voltage Law
D) both A and C

Question 46

Figure 16-8
The inverse of inductive reactance is:

A) impedance
B) resistance
C) inductive susceptance
D) capacitive susceptance

Question 47

In a series RL circuit where R = 100 Ω and XL = 50 Ω. What is the total impedance of this circuit?

A) 111.8 $\Omega \angle$
26.6°
B) 111.8 $\Omega \angle$
-26.6°
C) 111.8 $\Omega \angle$
-63.4°
D) 111.8 $\Omega \angle$
63.4°