Test 2

Calculate the total capacitive reactance XCT, where the values of series capacitive reactances are: XC1 = 10.5 kΩ, XC2 = 8.5 kΩ, and XC3 = 8.5 kΩ. Round the final answer to one decimal place.

27.5kΩ

Consider the circuit given below with voltage VA = 24 V peak, frequency f = 30 kHz, and capacitive reactance XC = 3 kΩ.

False

The circuit below has the following values: VT = 11 V XL = 191 Ω XC = 84 Ω In this circuit, XL and XC are 90° out of phase.

False

The voltage drop VC across the capacitive reactance XC leads current I by 90°.

False

n the circuit below: VT = 140 V, R = 55 Ω, XC = 160 Ω, and XL = 50 Ω. In this circuit, VC leads I by 90°.

False

Determine the total inductive reactance XLTXLT for series inductive reactances XL1XL1 = 12 kΩ, XL2XL2 = 32 kΩ, and XL3XL3 = 17 kΩ.

The total inductive reactance XLTXLT is calculated using the following formula: XLT =XL1 + XL2+ XL3= 12 kΩ + 32 kΩ + 17 kΩ = 61.0 kΩ

in the circuit below: VT = 140 V, R = 55 Ω, XC = 160 Ω, and XL = 50 Ω. XL and XC are 180° out of phase with each other.

True

In the circuit below: VA is 115 V, R is 290 Ω, XC is 35 Ω, and XL is 195 Ω. Are IL and IC 90° out of phase with each other?

No

Consider the circuit given below of a 25 V lamp with the switch S1 closed. The values of C1 = 113 μF and VT = 25 V. Determine the current I in the circuit. Round the final answer to the nearest whole number.

0

Calculate the capacitive reactance XC for the circuit given below with values Vac = 60 V and I = 50 μA. Round the final answer to two decimal places.

1200.00kΩ

Calculate the equivalent capacitive reactance XCEQ for the parallel capacitive reactances XC1 = 34 Ω, XC2 = 24 Ω, and XC3 = 190 Ω. Round the final answer to two decimal places.

13.10 Ω

Consider the circuit below, where VA = 220 V, resistor R = 66 Ω, and capacitive reactance XC = 40 Ω. Determine the voltage across the 66 Ω resistor R. Round the final answer to the nearest whole number.

220 V

Consider the circuit given below with voltage VA = 24 V peak, frequency f = 30 kHz, and capacitive reactance XC = 3 kΩ. What is the peak value of the capacitor voltage VC? Round the final answer to one decimal place.

24.0V

Consider the circuit given below of a 25 V lamp with the switch S1 closed. The values of C1 = 113 μF and VT = 25 V. Determine the direct current (dc) voltage VC across the capacitor. Round the final answer to the nearest whole number.

25 V

Consider the circuit given below. The capacitor and the lightbulb draw 280 mA from the 120-Vac source. Determine the current through the connecting wires. Round the final answer to the nearest whole number.

280 mA

Consider the circuit given below. The capacitor and the lightbulb draw 280 mA from the 120-Vac source. How much current flows to and from the plates of the capacitor. Round the final answer to the nearest whole number.

280 mA

Consider the circuit given below. The capacitor and the lightbulb draw 280 mA from the 120-Vac source. How much current flows to and from the terminals of the 120-Vac source. Round the final answer to the nearest whole number.

280 mA

Consider the circuit given below. The capacitor and the lightbulb draw 280 mA from the 120-Vac source. Determine the current through the lightbulb. Round the final answer to the nearest whole number.

280mA

Consider the circuit given below with voltage VA = 24 V peak, frequency f = 30 kHz, and capacitive reactance XC = 3 kΩ What is the peak value of the charge and discharge current iC? Round the final answer to two decimal places.

8.00mA

The phase angle θZ decreases when the frequency of the applied voltage increases.

False

The total current I in the circuit increases when the frequency of the applied voltage increases.

False

The total impedance ZT in the circuit decreases when the frequency of the applied voltage increases.

False

The circuit given below has the following values: V = 128 Vac and XL = 2.30 kΩ The current I in the circuit decreases when the frequency of the applied voltage decreases.

False The amount of current in an ac circuit with only inductive reactance is equal to the applied voltage divided by XL. Hence, the current in a circuit increases with a decrease in the frequency of the applied voltage.

A coil should have an inductive reactance XL of 1 Ω for a steady dc current.

False There is no XL for steady direct current. In this case, the coil is a resistance equal to the resistance of the wire.

The 90° phase relationship between the induced voltage and the inductor current exists because VL depends on the value of the current.

False For an inductor, the induced voltage VL always leads the current I by 90°.

Identify the factors that determine the amount of inductive reactance a coil will have. (Check all that apply.)

Frequency Inductance Inductive reactance is a measure of an inductor's opposition to the flow of alternating current.

In the circuit below, the inductive reactance XL will be 100 Ω when S1 is in position 1 as shown here.

In the given circuit, XL = 0 Ω with S1 in position 1. This is because the inductor has no inductive reactance for direct current. False

The circuit given below has the following values: V = 128 Vac and XL = 2.30 kΩ Does the current I in the circuit increase when the frequency of the applied voltage increases

NO The amount of current in an ac circuit with only inductive reactance is equal to the applied voltage divided by XL. Hence, the current in a circuit decreases with an increase in the frequency of the applied voltage.

In the circuit below: VA is 115 V, R is 290 Ω, XC is 35 Ω, and XL is 195 Ω. Will VA lead IC by 180° in this circuit?

No

In the circuit below: VT = 28 V, XL = 184 Ω, and XC = 124 Ω Will VT lead I by 90° if the values of XL and XC are interchanged?

No

n the circuit below: VT = 140 V, R = 55 Ω, XC = 160 Ω, and XL = 50 Ω. In this circuit, will VL lead I by 180°?

No

Identify a difference between resistance and impedance.

Resistance is the same for all frequencies, but impedance includes reactance which changes with frequency.

The current I and the voltage drop across resistance VR are in phase.

True

If the frequency of the applied voltage is increased, what is the effect on VR and VL? (Check all that apply.)

VR decreases VL increases

The circuit below has values: VT = 120 Vac, f = 18.085 kHz, L1 = 70 mH, L2 = 108 mH, and L3 = 166 mH. Determine inductive reactances XL1XL1 , XL2XL2 , and XL3XL3 and the value of series inductive reactance XLTXLT .

XL1 = 8 kΩ XL2 = 12kΩ XL3 = 19kΩ XLT = 39 kΩ The value of the inductive reactance XL1XL1⁢ is calculated using the following formula: XL1=2πfL1=(2×π×18.085 kHz×70 mH)=8 kΩXL1=2πfL1=(2×π×18.085 kHz×70 mH)=8 kΩ where f is the frequency and L1 is the inductance in the circuit. The value of the inductive reactance XL2XL2 is calculated using the following formula: XL2=2πfL2=2×π×(18.085 kHz×108 mH)=12 kΩXL2=2πfL2=2⁢×π×( 18.085 kHz×108 mH)⁢ =12 kΩ where f is the frequency and L2 is the inductance in the circuit. The value of the inductive reactance XL3XL3 is calculated using the following formula: XL3=2πfL3=(2×π×18.085 kHz×166 mH)=19 kΩXL3=2⁢ π⁢f⁢L3⁢=(2⁢ ×π⁢×18.085 kHz⁢×166 mH)⁢ = 19 kΩ⁢ where f is the frequency and L3 is the inductance in the circuit. The value of the series inductive reactance XLT is calculated using the following formula:

In the circuit below: VT = 28 V, XL = 184 Ω, and XC = 124 Ω In this circuit, will VC lag I by 90°?

Yes

n the circuit below: VT = 140 V, R = 55 Ω, XC = 160 Ω, and XL = 50 Ω. Are VL and VC 180° out of phase with each other?

Yes

n the circuit below: VT = 140 V, R = 55 Ω, XC = 160 Ω, and XL = 50 Ω. Are VR and I in phase in this circuit?

Yes

Calculate the capacitive reactance XC of a 0.1 μF capacitor at 40 Hz frequency. Round the final answer to two decimal places.

39.8kΩ

In the circuit below: VT = 130 V, R = 50 Ω, XC = 110 Ω, and XL = 50 Ω. Calculate the total impedance ZT in the circuit.

78.10 Ω

The circuit below has values: VT = 120 Vac, f = 18.085 kHz, L1 = 70 mH, L2 = 108 mH, and L3 = 166 mH.

Calculate the current I in the circuit. I=VT/XLT=120/V39 kΩ= 3.070 mA

The circuit below has the following values: VT = 11 V XL = 191 Ω XC = 84 Ω

Calculate the value of current I in the circuit. v/x=I 102.80mA

Define power factor.

It is a numerical ratio between 0 and 1 that specifies the ratio of real to apparent power in an ac circuit.

Does reactance XC change when current increases and the frequency stays the same?

No

In the circuit below: VA is 115 V, R is 290 Ω, XC is 35 Ω, and XL is 195 Ω. In this circuit, IL lags VA by 90°.

True

Inductive reactance XL increases when the frequency f of the applied voltage VT increases.

True

Identify a true statement about the phase relationship between VC and VR.

VC lags VR by 90°.

In the circuit below: VT = 28 V, XL = 184 Ω, and XC = 124 Ω Identify the phase relationship between VL and I.

VL leads I by 90°

For an inductor, what is the phase relationship between the induced voltage VL and the inductor current iL?

VL leads iL by a phase angle of 90°.

Consider the circuit given below of a 25 V lamp with the switch S1 closed. The values of C1 = 113 μF and VT = 25 V. Determine the direct current (dc) voltage across the lamp. Round the final answer to the nearest whole number. 0 0 Correct V

0

Consider the circuit given below. The capacitor and the lightbulb draw 280 mA from the 120-Vac source. Determine the current flow through the dielectric of the capacitor. Round the final answer to the nearest whole number.

0 A

Consider the circuit given below, where R = 20 Ω, XC = 30 Ω, and the corresponding voltage drops are VR = 35 V and VC = 52.5 V. Calculate the current I flowing through the capacitive reactance XC. Round the final answer to two decimal places.

1.75A

Consider the circuit given below, where R = 20 Ω, XC = 30 Ω, and the corresponding voltage drops are VR = 35 V and VC = 52.5 V. Calculate the current I flowing through the resistor R. Round the final answer to two decimal places.

1.75A

Consider the circuit given below, where R = 20 Ω, XC = 30 Ω, and the corresponding voltage drops are VR = 35 V and VC = 52.5 V. Calculate the current I flowing to and from the terminals of the applied voltage VT. Round the final answer to two decimal places.

1.75A

Consider the circuit below, where VA = 220 V, resistor R = 66 Ω, and capacitive reactance XC = 40 Ω. Determine the voltage across the 40 Ω capacitive reactance XC. Round the final answer to the nearest whole number.

220V

The circuit below has values: VT = 120 Vac, f = 18.085 kHz, L1 = 70 mH, L2 = 108 mH, and L3 = 166 mH. Determine the voltages across L1, L2, and L3 in the circuit.

24 37 57 The voltage VL1VL1 in the circuit is calculated using the following formula: VL1=IXL1=3.070 mA×8 kΩ=24.4 VVL1=I⁢XL1=3.070 mA× 8 kΩ=24.4 V where I is the current and XL1 is the inductive reactance of the circuit. The voltage VL2VL2 in the circuit is calculated using the following formula: VL2=IXL2=3.070 mA×12 kΩ=37.7 VVL2=IXL2=3.070 mA⁢ ×12 kΩ=37.7 V where I is the current and XL2XL2 is the inductive reactance of the circuit. The voltage VL3VL3 in the circuit is calculated using the following formula: VL3=IXL3=3.070 mA×19 kΩ=57.9 VVL3=IXL3=3.070 mA×19 kΩ= 57.9 V where I is the current and XL3XL3 is the inductive reactance of the circuit.

Consider the circuit given below with voltage VA = 24 V peak, frequency f = 30 kHz, and capacitive reactance XC = 3 kΩ. Determine the frequency of the charge and discharge current. Round the final answer to one decimal place.

30kHz

The circuit below has the following values: VT = 11 V XL = 191 Ω XC = 84 Ω

Calculate the inductor voltage VL and the capacitor voltage VC. VL= V*XL/X VL = 19.63 V VC= V*XC/X VC = 8.64 V

Consider the circuit below, where VA = 22 V, resistor R = 3 kΩ, and capacitive reactance XC = 1.2 kΩ. Calculate the current IR passing through the resistor R and IC passing through the capacitive reactance XC. Round the final answers to one decimal place.

IR= V/R IR = 7.3 mA IC= V/C IC = 18.3 mA

The circuit below has values: VT = 120 Vac, f = 18.085 kHz, L1 = 70 mH, L2 = 108 mH, and L3 = 166 mH. Calculate the total inductance LT in the circuit.

LT=XLT2πf=39 kΩ2π×18.085 kHz=344 mH

Identify the differences between inductive reactance and resistance. (Check all that apply.)

Resistance is the same for all frequencies, whereas inductive reactance increases for higher frequencies. The current is in phase with voltage in resistance, whereas the current lags voltage by 90° in inductive reactance. Inductive reactance is a measure of an inductor's opposition to the flow of alternating current. The symbol for inductive reactance is XL.

Calculate the inductive reactance XL of a 100 mH inductor at a frequency f of 3.001 kHz.

The inductive reactance XL is calculated using the following formula: XL=2πfL =2π×3.001 kHz×100mH=1.9 kΩXL=2πfL⁢=2π×3.001 kHz×100⁢ ⁢mH= 1.9 kΩ where f is the frequency and L is the inductance.

Three inductors in parallel have an equivalent inductance LEQ of 10.5 mH. If L2 = 3 L3 and L3 = 4 L1. Calculate the values of L1, L2, and L3.

The values of inductance are calculated using the following formula: 1/LEQ=1/L1+1/L2+1/L3= L1=16/12×LEQ=16/12×10.5 mH=14.00 mHL1=1612×LEQ⁢ =1612× 10.5 mH = 14.00 mH L3=4L1=4×14.00 mH =56.00 mHL3=4⁢L1=4⁢ × 14.00 mH =56.00 mH L2=3L3=3×56.00 mH = 168.00 mHL2=3⁢L3=3⁢×56.00 mH = 168.00 mH where L1, L2, and L3 are inductances.

In the circuit below: VA is 115 V, R is 290 Ω, XC is 35 Ω, and XL is 195 Ω. In this circuit, VA and IR are in phase.

True

In the circuit below: VT = 28 V, XL = 184 Ω, and XC = 124 Ω In this circuit VT leads I by 90°.

True

In the circuit below: VT = 130 V, R = 50 Ω, XC = 110 Ω, and XL = 50 Ω. Calculate the net reactance X.

XC-Xl=X 110-50=60

The circuit below has the following values: VT = 11 V XL = 191 Ω XC = 84 Ω Calculate the net reactance X.

XL-XC=X X=107 ohams

In the circuit below: VT = 28 V, XL = 184 Ω, and XC = 124 Ω Are VL and VC 180° out of phase in this circuit?

Yes