1. 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).
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 is the potential difference across a resistor in a circuit if the
current is 2A and the resistance is 4Ω?
A. 0.5V
B. 4V
C. 8V
D. 2V
Answer: c) 8V
Rationale: Using Ohm’s law, V=I×RV = I \times RV=I×R,
V=2A×4Ω=8VV = 2A \times 4Ω = 8VV=2A×4Ω=8V.
4. In an electrical circuit, the term "short circuit" refers to:
A. A circuit with high resistance
B. A circuit with no resistance
C. A circuit with low resistance
D. A circuit with alternating current
Answer: c) A circuit with low resistance
Rationale: A short circuit occurs when there is a path of very low
resistance, causing excessive current flow and potential damage to the
circuit.
, 5. In a parallel circuit, if the resistance of one resistor is increased, the
total current in the circuit will:
A. Decrease
B. Increase
C. Stay the same
D. Become zero
Answer: b) Increase
Rationale: In a parallel circuit, adding resistance to one path increases
the total resistance slightly, but the current tends to increase because
other paths for current are available.
6. In an AC circuit, what does the term 'frequency' refer to?
A. The speed at which current flows
B. The time it takes for the voltage to reach zero
C. The number of cycles per second
D. The voltage level
Answer: c) The number of cycles per second
Rationale: Frequency is the number of cycles of alternating current that
occur per second and is measured in Hertz (Hz).
7. What happens to the power consumed if both voltage and current
are doubled in a circuit?
A. Power remains the same
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).
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 is the potential difference across a resistor in a circuit if the
current is 2A and the resistance is 4Ω?
A. 0.5V
B. 4V
C. 8V
D. 2V
Answer: c) 8V
Rationale: Using Ohm’s law, V=I×RV = I \times RV=I×R,
V=2A×4Ω=8VV = 2A \times 4Ω = 8VV=2A×4Ω=8V.
4. In an electrical circuit, the term "short circuit" refers to:
A. A circuit with high resistance
B. A circuit with no resistance
C. A circuit with low resistance
D. A circuit with alternating current
Answer: c) A circuit with low resistance
Rationale: A short circuit occurs when there is a path of very low
resistance, causing excessive current flow and potential damage to the
circuit.
, 5. In a parallel circuit, if the resistance of one resistor is increased, the
total current in the circuit will:
A. Decrease
B. Increase
C. Stay the same
D. Become zero
Answer: b) Increase
Rationale: In a parallel circuit, adding resistance to one path increases
the total resistance slightly, but the current tends to increase because
other paths for current are available.
6. In an AC circuit, what does the term 'frequency' refer to?
A. The speed at which current flows
B. The time it takes for the voltage to reach zero
C. The number of cycles per second
D. The voltage level
Answer: c) The number of cycles per second
Rationale: Frequency is the number of cycles of alternating current that
occur per second and is measured in Hertz (Hz).
7. What happens to the power consumed if both voltage and current
are doubled in a circuit?
A. Power remains the same
