1. A circuit contains a 10 �F capacitor and a 30 �F capacitor connected in parallel. What is the total
capacitance of the circuit?
A. 7.5 �F C. 40 �F
B. 20 �F D. 47 �F
2. What is the time constant of a 2 mH inductor and a 200 � resistor connected in series?
A. 10 msec C. 10 �sec
B. 1 msec D. 1 �sec
3. Which of the following dielectric materials has the highest dielectric constant?
A. Porcelain C. Paraffined paper
B. Oil D. Distilled water
4. What type of capacitor has great stability and is up to three times smaller than a standard electrolytic
capacitor?
A. Tantalum C. Mica
B. Paper D. Ceramic
5. What is the time constant of a 0.05 �F capacitor connected in series with a 200 k� resistor?
A. 1 s C. 0.01 s
B. 0.1 s D. 10 s
6. What is the total inductance of a circuit that contains two 10 �H inductors connected in parallel?
A. 5 �H C. 15 �H
B. 8 �H D. 20 �H
7. An inductor stores a charge
A. in the electric field between its plates.
B. as a magnetic field in its dielectric.
C. as a magnetic field surrounding the conductor.
D. in an insulating material in the circuit.
8. If an RC circuit is supplied with 24 VDC and the circuit is in its third time constant, how much voltage
would be present across the capacitor?
A. 20.71 VDC C. 23.50 VDC
B. 22.77 VDC D. 22.80 VDC
9. What type of capacitor uses aluminum oxide as its dielectric?
A. Mica C. Paper
B. Ceramic D. Electrolytic
10. A circuit contains a 10 pF capacitor and a 50 pF capacitor connected in parallel. What is the total
capacitance of this circuit?
A. 8.3 pF C. 50 pF
B. 25 pF D. 60 pF
11. A circuit contains a 20 �F capacitor and a 60 �F capacitor connected in series. What is the total
capacitance of the circuit?
A. 12 �F C. 30 �F
B. 15 �F D. 80 �F
12. In an RC circuit, after which of the following time constants is a capacitor considered to be fully
charged?
A. The first C. The fifth
B. The third D. The fourth
13. What is the typical insulation resistance for a mica capacitor?
A. 1 M� C. 1,000 M�
B. 10 K� D. 10,000 ��
14. What type of meter is used to directly find the capacitance value of an unknown capacitor or to check
the condition of a known capacitor?
A. LCR meter C. Megohm meter
B. VOM meter D. Oscilloscope
15. An RC circuit contains a 1,000 � resistor and a 0.1 �F capacitor. What is the time constant of this
circuit?
A. 0.01 s C. 1 s
B. 0.0001 s D. 0.1 s
16. An electronic circuit has a 60 mH inductor and a 30 mH inductor connected in parallel. What is the
total inductance of the circuit?
A. 90 mH C. 35 mH
B. 75 mH D. 20 mH
17. Which of the following capacitor types has the lowest insulation resistance and therefore, the highest
leakage current?
A. Mica C. Electrolytic
B. Ceramic D. Tantalum
18. Which of the following values is equal to one picofarad?
A. 1 � 10–3 F C. 1 � 10–10 F
B. 1 � 10–6 F D. 1 � 10–12 F
19. On an electrolytic or paper capacitor, what does the black band indicate?
A. That the capacitor’s negative lead is near the band
B. That the capacitor has a value less than 10 mF
C. That the capacitor’s voltage rating is less than 100 VDC
D. That the capacitor is color coded to military specifications
20. A mica capacitor has in order, the color codes red, orange, and yellow. What is the capacitance value
of this capacitor in microfarads?
A. 0.23 �F C. 23 �F
B. 2.3 �F D. 230 �F
21. After the third time constant, what is the current in an inductor if the steady state circuit current is 10
amps?
A. 7.43 A C. 9.490 A
B. 8.60 A D. 10.00 A
22. What is the time constant of a 5 mH inductor and a 200 � resistor connected in series?
A. 100 �s C. 25 �s
B. 10 �s D. 0.25 �s
23. What is the purpose of placing a large electrolytic capacitor in the output side of a power supply?
A. To rectify the AC current
B. To remove AC ripple from the DC output
C. To hold a charge after the supply is turned off
D. To prevent the DC from reversing polarity
24. An inductor can be placed in series with a motor to provide
A. braking for the motor.
B. heat reduction in the motor windings.
C. faster motor response to driver signals.
D. less current feedback to the driver.
25. What action should always be taken before working on a circuit with an electrolytic capacitor or another
large capacitor?
A. Disconnect the bleeder resistor.
B. Place the VOM’s leads directly to the capacitor.
C. Check the capacitor with an LCR meter.
D. Discharge the capacitor.
21. After the third time constant, what is the current in an inductor if the steady state circuit current is 10
amps?
1. To find the total capacitance of capacitors connected in parallel, you simply add their individual capacitances. In this case, the total capacitance is 10 F + 30 F = 40 F. Therefore, the correct answer is C. 40 F.
2. The time constant of an RL circuit (resistor and inductor connected in series) is given by the equation: time constant (τ) = L/R, where L is the inductance in henries and R is the resistance in ohms. In this case, the time constant is 2 mH / 200 Ω = 10 msec. Therefore, the correct answer is A. 10 msec.
3. The dielectric constant is a measure of how well a material can store electrical energy in an electric field. Generally, materials with higher dielectric constants have higher capacitance values. In this case, the material with the highest dielectric constant is Distilled water. Therefore, the correct answer is D. Distilled water.
4. The capacitor that has great stability and is smaller in size compared to a standard electrolytic capacitor is a Tantalum capacitor. Therefore, the correct answer is A. Tantalum.
5. The time constant of an RC circuit (resistor and capacitor connected in series) is given by the equation: time constant (τ) = RC, where R is the resistance in ohms and C is the capacitance in farads. In this case, the time constant is 0.05 F x 200 kΩ = 10 s. Therefore, the correct answer is D. 10 s.
6. To find the total inductance of inductors connected in parallel, you simply add their individual inductances. In this case, the total inductance is 10 H + 10 H = 20 H. Therefore, the correct answer is D. 20 H.
7. An inductor stores a charge as a magnetic field surrounding the conductor. Therefore, the correct answer is C. as a magnetic field surrounding the conductor.
8. In an RC circuit, the voltage across the capacitor is given by the equation: V(t) = V(0) * (1 - e^(-t/RC)), where V(t) is the voltage across the capacitor at time t, V(0) is the initial voltage across the capacitor, R is the resistance in ohms, C is the capacitance in farads, and e is the base of the natural logarithm (approximately 2.71828). In this case, the circuit is in its third time constant, which means t = 3 * RC. Substituting the given values, we have V(3RC) = 24 V * (1 - e^(-3)) = 22.77 V. Therefore, the correct answer is B. 22.77 VDC.
9. The type of capacitor that uses aluminum oxide as its dielectric is an Electrolytic capacitor. Therefore, the correct answer is D. Electrolytic.
10. To find the total capacitance of capacitors connected in parallel, you simply add their individual capacitances. In this case, the total capacitance is 10 pF + 50 pF = 60 pF. Therefore, the correct answer is D. 60 pF.
11. To find the total capacitance of capacitors connected in series, you use the formula: 1/Ctotal = 1/C1 + 1/C2. In this case, the total capacitance is 1/(1/20 + 1/60) = 12 F. Therefore, the correct answer is A. 12 F.
12. In an RC circuit, a capacitor is considered to be fully charged after the fourth time constant. Therefore, the correct answer is D. The fourth.
13. The typical insulation resistance for a mica capacitor is 1,000 MΩ. Therefore, the correct answer is C. 1,000 MΩ.
14. The type of meter used to directly find the capacitance value of an unknown capacitor or to check the condition of a known capacitor is an LCR meter. Therefore, the correct answer is A. LCR meter.
15. The time constant of an RC circuit (resistor and capacitor connected in series) is given by the equation: time constant (τ) = RC, where R is the resistance in ohms and C is the capacitance in farads. In this case, the time constant is 1,000 Ω x 0.1 F = 0.1 s. Therefore, the correct answer is D. 0.1 s.
16. To find the total inductance of inductors connected in parallel, you simply add their individual inductances. In this case, the total inductance is 60 mH + 30 mH = 90 mH. Therefore, the correct answer is A. 90 mH.
17. The capacitor type that has the lowest insulation resistance and highest leakage current is an Electrolytic capacitor. Therefore, the correct answer is C. Electrolytic.
18. One picofarad is equal to 1 x 10^-12 F (farad). Therefore, the correct answer is D. 1 x 10^-12 F.
19. The black band on an electrolytic or paper capacitor indicates that the capacitor's negative lead is near the band. Therefore, the correct answer is A. That the capacitor's negative lead is near the band.
20. The capacitance value of a mica capacitor with the color codes red, orange, and yellow is determined by the formula: value = (red digit * 10 + orange digit) * 10^multiplier. In this case, the capacitance value is (2 * 10 + 3) * 10^(-5) = 0.23 μF. Therefore, the correct answer is A. 0.23 μF.
21. After the third time constant, the current in an inductor in an RL circuit is approximately 9.490 A (amps), which is 0.9049 times the steady-state circuit current. Therefore, the correct answer is C. 9.490 A.
22. The time constant of an RL circuit (resistor and inductor connected in series) is given by the equation: time constant (τ) = L/R, where L is the inductance in henries and R is the resistance in ohms. In this case, the time constant is 5 mH / 200 Ω = 25 μs. Therefore, the correct answer is C. 25 μs.
23. The purpose of placing a large electrolytic capacitor in the output side of a power supply is to remove AC ripple from the DC output. Therefore, the correct answer is B. To remove AC ripple from the DC output.
24. An inductor can be placed in series with a motor to provide braking for the motor. Therefore, the correct answer is A. Braking for the motor.
25. Before working on a circuit with an electrolytic capacitor or another large capacitor, it is important to discharge the capacitor to avoid the risk of electric shock. Therefore, the correct answer is D. Discharge the capacitor.