CHAPTER 16: ALTERNATING CURRENT CIRCUIT ANALYSIS

Suppose that in a series RLC circuit, R = 50 Ω and no net reactance exists. In which

direction does the complex-impedance vector point?

(a) Straight up

(b) Straight down

(c) Straight toward the right

(d) Downward and toward the right

C

Suppose that in a parallel RLC circuit, G = 0.05 S and B = -0.05 S. In which direction does

the complex-admittance (not the complex-impedance) vector point?

(a) Straight down

(b) Straight toward the right

(c) Upward and toward the right

(d) Downward and toward the right

D

Suppose that in a parallel RLC circuit, R = 10 Ω and jXC = -j10. In which direction

does the complex-admittance (not the complex-impedance) vector point?

(a) Straight up

(b) Straight toward the right

(c) Upward and toward the right

(d) Downward and toward the right

C

A vector pointing upward and toward the right in the GB half-plane would indicate

(a) pure conductance.

(b) conductance and inductive susceptance.

(c) conductance and capacitive susceptance.

(d) None of the above

C

A vector pointing upward and toward the left in the RX half-plane would indicate

(a) pure resistance.

(b) resistance and inductive reactance.

(c) resistance and capacitive reactance.

(d) None of the above

D

Suppose that a coil has a reactance of j 20 Ω. What's the susceptance, assuming that the

circuit contains nothing else?

(a) j 0.050 S

(b) -j 0.050 S

(c) j 20 S

(d) -j 20 S

B

Suppose that a capacitor has a susceptance of j 0.040 S. What's the reactance, assuming that

the circuit contains nothing else?

(a) j 0.040 Ω

(b) -j 0.040 Ω

(c) j 25 Ω

(d) -j 25 Ω

D

Suppose that we connect a coil and capacitor in series with j XL = j 50 and j XC = -j 100.

What's the net reactance?

(a) j 50

(b) j 150

(c) -j 50

(d) -j 150

C

Suppose that we connect a coil of L = 3.00 μH and a capacitor of C = 100 pF in series, and

then drive an AC signal through the combination at a frequency of f = 6.00 MHz. What's the net

reactance?

(a) -j 152

(b) -j 378

(c) j 152

(d) j 378

A

Consider a resistor, a coil, and a capacitor in series with R = 10 Ω, XL = 72 Ω, and

XC = -83 Ω. What's the net impedance Z?

(a) 10 + j 11

(b) 10 - j 11

(c) 82 - j 11

(d) -73 - j 11

B

Consider a resistor, a coil, and a capacitor connected in series. The resistor has a value of

220.0 Ω, the capacitance equals 500.00 pF, and the inductance equals 44.00 μH. We operate

the circuit at a frequency of 5.650 MHz. What's the complex impedance?

(a) 220.0 + j 1506

(b) 220.0 - j 1506

(c) 0.000 + j 1506

(d) 220.0 + j 0

A

Suppose that we connect a resistor, a coil, and a capacitor in series. The resistance equals

75.3 Ω, the inductance equals 8.88 μH, and the capacitance equals 980 pF. We operate the

circuit at a frequency of 1340 kHz. What's the complex impedance?

(a) 75.3 + j 0.00

(b) 75.3 + j 46.4

(c) 75.3 - j 46.4

(d) 0.00 - j 75.3

C

Consider a coil and capacitor connected in parallel with jBL = -j 0.32 and jBC = j 0.20.

What's the net susceptance?

(a) j 0.52

(b) -j 0.52

(c) j 0.12

(d) -j 0.12

D

Suppose that we connect a coil of 8.5 μH and a capacitor of 100 pF in parallel and drive a

signal through them at 7.10 MHz. What's the net susceptance?

(a) -j 0.0045

(b) j 0.0018

(c) -j 0.0026

(d) None of the above

B

What's the net susceptance of the parallel-connected inductor and capacitor described in

Question 14 if we double the frequency to 14.2 MHz?

(a) -j 0.0090

(b) j 0.0036

(c) -j 0.0013

(d) None of the above

D

Consider a resistor, a coil, and a capacitor in parallel. The resistance is 7.50 Ω, the

inductance is 22.0 μH, and the capacitance is 100 pF. The frequency is 5.33 MHz. What's

the complex admittance?

(a) 0.133 + j 0.00199

(b) 0.133 - j 0.00199

(c) 7.50 + j 503

(d) 7.50 - j 503

A

Suppose that a circuit has an admittance of Y = 0.333 + j 0.667. What's the complex

impedance, assuming the frequency does not change?

(a) 1.80 - j 0.833

(b) 1.80 + j 0.833

(c) 0.599 - j 1.20

(d) 0.599 + j 1.20

C

Suppose that we connect a resistor of 25 Ω, a capacitor of 0.0020 μF, and a coil of

7.7 μH in parallel (not in series!). We operate the circuit at 2.0 MHz. What's the complex

impedance?

(a) 8.1 + j 22

(b) 8.1 - j 22

(c) 22 + j 8.1

(d) 22 - j 8.1

D

Suppose that a series RX circuit has a resistance of R = 20 Ω and a capacitive reactance of

X = -20 Ω. Suppose that we apply 42 V RMS AC to this circuit. How much current flows?

(a) 0.67 A RMS

(b) 1.5 A RMS

(c) 2.3 A RMS

(d) 3.0 A RMS

B

Suppose that a parallel RX circuit has R = 50 Ω and X = 40 Ω. We supply the circuit

with E = 155 V RMS. How much current does the entire circuit draw from the AC source?

(a) 5.0 A RMS

(b) 2.5 A RMS

(c) 400 mA RMS

(d) 200 mA RMS

A