Current Electricity Study Materials for Competitive Exams

Current Electricity

Q. A 100W bulb operates at 220V. What is the resistance of the bulb? (2021)

A. 484Ω
B. 220Ω
C. 110Ω
D. 100Ω

Solution

Using P = V^2/R, we rearrange to find R = V^2/P = (220V)^2 / 100W = 484Ω.

Correct Answer: A — 484Ω

Learn More →

Q. A 12V battery is connected across a 4Ω resistor. What is the current flowing through the resistor? (2020)

A. 2A
B. 3A
C. 4A
D. 6A

Solution

Using Ohm's law, I = V/R = 12V / 4Ω = 3A.

Correct Answer: A — 2A

Learn More →

Q. A 12V battery is connected to a resistor of 4Ω. What is the current flowing through the circuit? (2022)

A. 2A
B. 3A
C. 4A
D. 1A

Solution

Using Ohm's law, I = V/R = 12V / 4Ω = 3A.

Correct Answer: A — 2A

Learn More →

Q. A circuit consists of a 9V battery and two resistors of 3Ω and 6Ω in series. What is the current flowing through the circuit? (2021)

A. 1A
B. 2A
C. 3A
D. 4A

Solution

Total resistance R = 3Ω + 6Ω = 9Ω. Current I = V/R = 9V / 9Ω = 1A.

Correct Answer: B — 2A

Learn More →

Q. A circuit has a 9V battery and two resistors of 3Ω and 6Ω in series. What is the current flowing through the circuit? (2022)

A. 1A
B. 2A
C. 3A
D. 4A

Solution

Total resistance R = 3Ω + 6Ω = 9Ω. Current I = V/R = 9V / 9Ω = 1A.

Correct Answer: B — 2A

Learn More →

Q. A circuit has a total resistance of 12Ω and a current of 1.5A. What is the voltage across the circuit? (2021)

A. 18V
B. 12V
C. 15V
D. 9V

Solution

Using Ohm's law, V = IR = 1.5A * 12Ω = 18V.

Correct Answer: A — 18V

Learn More →

Q. A circuit has a total resistance of 20Ω and a current of 2A flowing through it. What is the voltage across the circuit? (2023)

A. 30V
B. 40V
C. 20V
D. 10V

Solution

Using Ohm's law, V = I * R = 2A * 20Ω = 40V.

Correct Answer: B — 40V

Learn More →

Q. A circuit has a total voltage of 24V and a total resistance of 8Ω. What is the total current in the circuit? (2020)

A. 3A
B. 2A
C. 4A
D. 6A

Solution

Using Ohm's law, I = V/R = 24V / 8Ω = 3A.

Correct Answer: A — 3A

Learn More →

Q. A resistor of 10Ω is connected to a 20V battery. What is the power consumed by the resistor? (2021)

A. 40W
B. 20W
C. 10W
D. 2W

Solution

Power (P) is given by P = V^2/R = (20V)^2 / 10Ω = 400/10 = 40W.

Correct Answer: A — 40W

Learn More →

Q. A resistor of 10Ω is connected to a 20V power supply. What is the power consumed by the resistor? (2021)

A. 40W
B. 20W
C. 10W
D. 2W

Solution

Power (P) is given by P = V^2/R = (20V)^2 / 10Ω = 400/10 = 40W.

Correct Answer: A — 40W

Learn More →

Q. If a 10Ω resistor is connected in parallel with a 5Ω resistor, what is the equivalent resistance? (2022)

A. 3.33Ω
B. 5Ω
C. 7.5Ω
D. 15Ω

Solution

For parallel resistors, 1/R_eq = 1/R1 + 1/R2 = 1/10 + 1/5 = 1/10 + 2/10 = 3/10. Therefore, R_eq = 10/3 = 3.33Ω.

Correct Answer: A — 3.33Ω

Learn More →

Q. If a 10Ω resistor is connected in parallel with a 5Ω resistor, what is the total resistance? (2022)

A. 3.33Ω
B. 5Ω
C. 7.5Ω
D. 15Ω

Solution

For resistors in parallel, 1/R_eq = 1/R1 + 1/R2 = 1/10 + 1/5 = 1/10 + 2/10 = 3/10. Therefore, R_eq = 10/3 = 3.33Ω.

Correct Answer: A — 3.33Ω

Learn More →

Q. If a 15Ω resistor is connected in parallel with a 5Ω resistor, what is the equivalent resistance? (2023)

A. 3.75Ω
B. 4Ω
C. 5Ω
D. 10Ω

Solution

1/R_eq = 1/15 + 1/5 = 1/15 + 3/15 = 4/15; R_eq = 15/4 = 3.75Ω.

Correct Answer: A — 3.75Ω

Learn More →

Q. If a 5Ω resistor is connected in series with a 10Ω resistor, what is the total resistance? (2022)

A. 15Ω
B. 5Ω
C. 10Ω
D. 20Ω

Solution

In series, R_eq = R1 + R2 = 5Ω + 10Ω = 15Ω.

Correct Answer: A — 15Ω

Learn More →

Q. If a 5Ω resistor is connected to a 10V source, what is the power dissipated? (2023)

A. 2W
B. 5W
C. 10W
D. 20W

Solution

Power P = V²/R = (10V)² / 5Ω = 100 / 5 = 20W.

Correct Answer: C — 10W

Learn More →

Q. If a 6Ω resistor is connected in parallel with a 3Ω resistor, what is the equivalent resistance? (2023)

A. 2Ω
B. 1.5Ω
C. 4Ω
D. 9Ω

Solution

Using the formula 1/R_eq = 1/R1 + 1/R2, we get 1/R_eq = 1/6 + 1/3 = 1/6 + 2/6 = 3/6, thus R_eq = 2Ω.

Correct Answer: A — 2Ω

Learn More →

Q. If a 9V battery is connected to a 3Ω resistor, what is the current flowing through it? (2021)

A. 1A
B. 2A
C. 3A
D. 4A

Solution

Using Ohm's law, I = V/R = 9V / 3Ω = 3A.

Correct Answer: B — 2A

Learn More →

Q. If a 9V battery is connected to a 3Ω resistor, what is the voltage drop across the resistor? (2023)

A. 3V
B. 6V
C. 9V
D. 12V

Solution

The voltage drop across the resistor is equal to the battery voltage, which is 9V.

Correct Answer: C — 9V

Learn More →

Q. If a circuit has a total resistance of 12Ω and a current of 1.5A flows through it, what is the voltage across the circuit? (2022)

A. 18V
B. 12V
C. 15V
D. 10V

Solution

Using Ohm's law, V = IR = 1.5A * 12Ω = 18V.

Correct Answer: A — 18V

Learn More →

Q. If a circuit has a total resistance of 12Ω and a current of 1.5A, what is the voltage across the circuit? (2021)

A. 18V
B. 12V
C. 15V
D. 10V

Solution

Using Ohm's law, V = IR = 1.5A * 12Ω = 18V.

Correct Answer: A — 18V

Learn More →

Q. If a circuit has a total resistance of 12Ω and a current of 3A flows through it, what is the voltage across the circuit? (2020)

A. 36V
B. 12V
C. 4V
D. 24V

Solution

Using Ohm's law, V = IR = 3A * 12Ω = 36V.

Correct Answer: A — 36V

Learn More →

Q. If a circuit has a total resistance of 12Ω and a current of 4A, what is the voltage across the circuit? (2023)

A. 48V
B. 36V
C. 24V
D. 12V

Solution

Using Ohm's law, V = IR = 4A * 12Ω = 48V.

Correct Answer: A — 48V

Learn More →

Q. If a circuit has a total resistance of 5Ω and a current of 2A, what is the voltage across the circuit? (2022)

A. 10V
B. 5V
C. 2V
D. 1V

Solution

Using Ohm's law, V = I * R = 2A * 5Ω = 10V.

Correct Answer: A — 10V

Learn More →

Q. If a circuit has a total resistance of 8Ω and a current of 4A, what is the voltage across the circuit? (2023)

A. 32V
B. 24V
C. 16V
D. 12V

Solution

Using Ohm's law, V = IR = 4A * 8Ω = 32V.

Correct Answer: A — 32V

Learn More →

Q. If the current through a resistor is tripled, what happens to the power dissipated in the resistor? (2022)

A. Increases by 3 times
B. Increases by 9 times
C. Remains the same
D. Decreases by 3 times

Solution

Power is proportional to the square of the current (P = I²R). If I is tripled, P increases by 3² = 9 times.

Correct Answer: B — Increases by 9 times

Learn More →

Q. If the resistance of a conductor is doubled, what happens to the current flowing through it when the voltage remains constant? (2022)

A. Doubles
B. Halves
C. Remains the same
D. Increases by 1.5 times

Solution

According to Ohm's law, I = V/R. If R is doubled, I will be halved.

Correct Answer: B — Halves

Learn More →

Q. If the voltage across a resistor is halved, what happens to the current through it? (2020)

A. It doubles
B. It halves
C. It remains the same
D. It quadruples

Solution

According to Ohm's law, if voltage is halved and resistance remains constant, the current also halves.

Correct Answer: B — It halves

Learn More →

Q. If two resistors of 4Ω and 6Ω are connected in series, what is the total resistance? (2023)

A. 10Ω
B. 24Ω
C. 2.4Ω
D. 12Ω

Solution

In series, R_eq = R1 + R2 = 4Ω + 6Ω = 10Ω.

Correct Answer: A — 10Ω

Learn More →

Q. In a circuit with a 24V battery and two 8Ω resistors in series, what is the total current? (2022)

A. 1A
B. 2A
C. 3A
D. 4A

Solution

Total resistance R = 8Ω + 8Ω = 16Ω. Current I = V/R = 24V / 16Ω = 1.5A.

Correct Answer: B — 2A

Learn More →

Q. In a circuit with a 24V battery and two resistors of 4Ω and 8Ω in parallel, what is the total current supplied by the battery? (2022)

A. 3A
B. 2A
C. 4A
D. 6A

Solution

First, find the equivalent resistance: 1/R_eq = 1/4 + 1/8 = 3/8, so R_eq = 8/3Ω. Then, I = V/R_eq = 24V / (8/3)Ω = 9A.

Correct Answer: D — 6A

Learn More →

Showing 1 to 30 of 62 (3 Pages)

Current Electricity

On a scale of 0–10, how likely are you to recommend The Soulshift Academy?