1. What is the resistance of a 3Ω resistor and a 6Ω resistor in series?
A. 9Ω
B. 18Ω
C. 2Ω
D. 3Ω
Answer: a) 9Ω
Rationale: In a series circuit, the total resistance is the sum of
individual resistances. So, Rtotal=3Ω+6Ω=9ΩR_{total} = 3Ω + 6Ω =
9ΩRtotal=3Ω+6Ω=9Ω.
2. Which of the following is the correct formula for electrical power?
A. P=V×IP = V \times IP=V×I
B. P=V2×RP = V^2 \times RP=V2×R
C. P=I2×RP = I^2 \times RP=I2×R
D. All of the above
Answer: d) All of the above
Rationale: All three formulas are correct, depending on the known
quantities:
• P=V×IP = V \times IP=V×I
• P=V2RP = \frac{V^2}{R}P=RV2
,• P=I2×RP = I^2 \times RP=I2×R
3. What happens if the voltage across a resistor in a circuit is doubled?
A. The current stays the same
B. The current doubles
C. The current quadruples
D. The current is halved
Answer: b) The current doubles
Rationale: According to Ohm's law, I=VRI = \frac{V}{R}I=RV, so if
the voltage doubles, the current will also double (assuming resistance
stays the same).
4. In an AC circuit, the voltage and current are both:
A. Constant
B. Zero
C. Alternating
D. Always in phase
Answer: c) Alternating
Rationale: In an alternating current (AC) circuit, both the voltage and
current continuously change direction, hence they are alternating.
5. What is the function of a resistor in an electrical circuit?
, A. To store energy
B. To control the flow of current
C. To increase voltage
D. To change AC to DC
Answer: b) To control the flow of current
Rationale: A resistor is used in a circuit to limit the current flow by
providing resistance.
6. If a 60W light bulb is used for 5 hours, how much energy is
consumed?
A. 300 J
B. 300 Wh
C. 60 J
D. 5 kWh
Answer: b) 300 Wh
Rationale: Energy consumed is E=P×t=60W×5h=300WhE = P
\times t = 60W \times 5h = 300WhE=P×t=60W×5h=300Wh.
7. What does a multimeter measure?
A. Only current
B. Only voltage
C. Current, voltage, and resistance
A. 9Ω
B. 18Ω
C. 2Ω
D. 3Ω
Answer: a) 9Ω
Rationale: In a series circuit, the total resistance is the sum of
individual resistances. So, Rtotal=3Ω+6Ω=9ΩR_{total} = 3Ω + 6Ω =
9ΩRtotal=3Ω+6Ω=9Ω.
2. Which of the following is the correct formula for electrical power?
A. P=V×IP = V \times IP=V×I
B. P=V2×RP = V^2 \times RP=V2×R
C. P=I2×RP = I^2 \times RP=I2×R
D. All of the above
Answer: d) All of the above
Rationale: All three formulas are correct, depending on the known
quantities:
• P=V×IP = V \times IP=V×I
• P=V2RP = \frac{V^2}{R}P=RV2
,• P=I2×RP = I^2 \times RP=I2×R
3. What happens if the voltage across a resistor in a circuit is doubled?
A. The current stays the same
B. The current doubles
C. The current quadruples
D. The current is halved
Answer: b) The current doubles
Rationale: According to Ohm's law, I=VRI = \frac{V}{R}I=RV, so if
the voltage doubles, the current will also double (assuming resistance
stays the same).
4. In an AC circuit, the voltage and current are both:
A. Constant
B. Zero
C. Alternating
D. Always in phase
Answer: c) Alternating
Rationale: In an alternating current (AC) circuit, both the voltage and
current continuously change direction, hence they are alternating.
5. What is the function of a resistor in an electrical circuit?
, A. To store energy
B. To control the flow of current
C. To increase voltage
D. To change AC to DC
Answer: b) To control the flow of current
Rationale: A resistor is used in a circuit to limit the current flow by
providing resistance.
6. If a 60W light bulb is used for 5 hours, how much energy is
consumed?
A. 300 J
B. 300 Wh
C. 60 J
D. 5 kWh
Answer: b) 300 Wh
Rationale: Energy consumed is E=P×t=60W×5h=300WhE = P
\times t = 60W \times 5h = 300WhE=P×t=60W×5h=300Wh.
7. What does a multimeter measure?
A. Only current
B. Only voltage
C. Current, voltage, and resistance
