1|Page
NEIEP 600 FINAL EXAM TEST BANK
Complete Questions & Answers (A+ Graded 100%
Verified)
With Detailed Rationales | 2026-2027 Edition
Topic 1: Capacitors and RC Circuits (Questions 1-20)
1. In capacitors, what is the purpose of the dielectric?
• A) To increase the capacitor's physical size
• B) To prevent arcing between the plates
• C) To decrease the capacitor's voltage rating
• D) To serve as a conductor for current flow
Correct Answer: B) To prevent arcing between the plates
Rationale: The dielectric is an insulating material placed between the
two conductive plates of a capacitor. Its primary function is to prevent
direct contact between the plates, which would cause a short circuit and
arcing, while allowing an electric field to form and store energy .
2. What describes a capacitor's ability to store an electrical charge?
• A) Resistance
• B) Inductance
• C) Capacitance
,2|Page
• D) Reactance
Correct Answer: C) Capacitance
Rationale: Capacitance, measured in farads (F), is the property of a
capacitor that defines its ability to store an electrical charge. It is
determined by the plate area, the distance between plates, and the
dielectric material used .
3. What is the time constant (TC) for a circuit with a 150k ohm
resistor and a 2 microfarad capacitor?
• A) 0.03 seconds
• B) 0.3 seconds
• C) 3.0 seconds
• D) 300 seconds
Correct Answer: B) 0.3 seconds
Rationale: The time constant for an RC circuit is calculated using the
formula TC = R × C. With R = 150,000 ohms and C = 0.000002 farads,
the product is 0.3 seconds. This represents the time it takes for the
capacitor to charge to approximately 63.2% of the source voltage .
4. Which statement best describes one time constant of a capacitor?
• A) The time it takes to charge to 100% of the applied voltage
• B) The time it takes to discharge to 0% of the applied voltage
• C) The time it takes to charge to 63.2% of the applied voltage
• D) The time it takes to reach the same voltage as the source
,3|Page
Correct Answer: C) The time it takes to charge to 63.2% of the
applied voltage
Rationale: One time constant (1τ) in an RC circuit is the duration
required for the capacitor voltage to rise to approximately 63.2% of the
applied voltage during the charging phase or to fall to 36.8% during the
discharging phase .
5. In a DC circuit, which is correct about capacitors the instant
when power is applied?
• A) Voltage is maximum and current is zero
• B) Voltage and current are both maximum
• C) Current is maximum and voltage is minimum
• D) Voltage and current are both zero
Correct Answer: C) Current is maximum and voltage is minimum
Rationale: At the initial moment power is applied to an RC circuit, the
uncharged capacitor acts as a short circuit. This results in maximum
current flow and a minimum (zero) voltage across the capacitor .
6. If a circuit has a capacitor of 5 microfarads and a source voltage
of 120 volts DC through a resistance of 200k ohms, how long will it
take to fully charge?
• A) 1 second
• B) 5 seconds
• C) 10 seconds
, 4|Page
• D) 15 seconds
Correct Answer: B) 5 seconds
Rationale: A capacitor is generally considered fully charged after 5 time
constants (5τ). First, calculate one time constant: TC = R × C = 200,000
ohms × 0.000005 farads = 1 second. Therefore, 5TC = 5 seconds .
7. Which of the following is true about capacitors in AC circuits?
• A) Voltage leads current by 90 degrees
• B) Current and voltage are in phase
• C) Current leads voltage by 90 degrees
• D) Current lags voltage by 90 degrees
Correct Answer: C) Current leads voltage by 90 degrees
Rationale: In a purely capacitive AC circuit, the current reaches its peak
before the voltage does. This is because the current must flow to build
up charge on the plates, which then creates the voltage. The phase
difference is 90 degrees .
8. Which statement is correct regarding capacitors?
• A) Placing two capacitors in series increases the capacitance
• B) Placing two capacitors in series decreases the capacitance
• C) Placing two capacitors in parallel decreases the capacitance
• D) The total capacitance in series is the sum of the individual
capacitances
NEIEP 600 FINAL EXAM TEST BANK
Complete Questions & Answers (A+ Graded 100%
Verified)
With Detailed Rationales | 2026-2027 Edition
Topic 1: Capacitors and RC Circuits (Questions 1-20)
1. In capacitors, what is the purpose of the dielectric?
• A) To increase the capacitor's physical size
• B) To prevent arcing between the plates
• C) To decrease the capacitor's voltage rating
• D) To serve as a conductor for current flow
Correct Answer: B) To prevent arcing between the plates
Rationale: The dielectric is an insulating material placed between the
two conductive plates of a capacitor. Its primary function is to prevent
direct contact between the plates, which would cause a short circuit and
arcing, while allowing an electric field to form and store energy .
2. What describes a capacitor's ability to store an electrical charge?
• A) Resistance
• B) Inductance
• C) Capacitance
,2|Page
• D) Reactance
Correct Answer: C) Capacitance
Rationale: Capacitance, measured in farads (F), is the property of a
capacitor that defines its ability to store an electrical charge. It is
determined by the plate area, the distance between plates, and the
dielectric material used .
3. What is the time constant (TC) for a circuit with a 150k ohm
resistor and a 2 microfarad capacitor?
• A) 0.03 seconds
• B) 0.3 seconds
• C) 3.0 seconds
• D) 300 seconds
Correct Answer: B) 0.3 seconds
Rationale: The time constant for an RC circuit is calculated using the
formula TC = R × C. With R = 150,000 ohms and C = 0.000002 farads,
the product is 0.3 seconds. This represents the time it takes for the
capacitor to charge to approximately 63.2% of the source voltage .
4. Which statement best describes one time constant of a capacitor?
• A) The time it takes to charge to 100% of the applied voltage
• B) The time it takes to discharge to 0% of the applied voltage
• C) The time it takes to charge to 63.2% of the applied voltage
• D) The time it takes to reach the same voltage as the source
,3|Page
Correct Answer: C) The time it takes to charge to 63.2% of the
applied voltage
Rationale: One time constant (1τ) in an RC circuit is the duration
required for the capacitor voltage to rise to approximately 63.2% of the
applied voltage during the charging phase or to fall to 36.8% during the
discharging phase .
5. In a DC circuit, which is correct about capacitors the instant
when power is applied?
• A) Voltage is maximum and current is zero
• B) Voltage and current are both maximum
• C) Current is maximum and voltage is minimum
• D) Voltage and current are both zero
Correct Answer: C) Current is maximum and voltage is minimum
Rationale: At the initial moment power is applied to an RC circuit, the
uncharged capacitor acts as a short circuit. This results in maximum
current flow and a minimum (zero) voltage across the capacitor .
6. If a circuit has a capacitor of 5 microfarads and a source voltage
of 120 volts DC through a resistance of 200k ohms, how long will it
take to fully charge?
• A) 1 second
• B) 5 seconds
• C) 10 seconds
, 4|Page
• D) 15 seconds
Correct Answer: B) 5 seconds
Rationale: A capacitor is generally considered fully charged after 5 time
constants (5τ). First, calculate one time constant: TC = R × C = 200,000
ohms × 0.000005 farads = 1 second. Therefore, 5TC = 5 seconds .
7. Which of the following is true about capacitors in AC circuits?
• A) Voltage leads current by 90 degrees
• B) Current and voltage are in phase
• C) Current leads voltage by 90 degrees
• D) Current lags voltage by 90 degrees
Correct Answer: C) Current leads voltage by 90 degrees
Rationale: In a purely capacitive AC circuit, the current reaches its peak
before the voltage does. This is because the current must flow to build
up charge on the plates, which then creates the voltage. The phase
difference is 90 degrees .
8. Which statement is correct regarding capacitors?
• A) Placing two capacitors in series increases the capacitance
• B) Placing two capacitors in series decreases the capacitance
• C) Placing two capacitors in parallel decreases the capacitance
• D) The total capacitance in series is the sum of the individual
capacitances
