Question

A current of 3 A flows through a resistor of resistance 4 Ω for 2 minutes. The heat produced is:

• A. 4320 J
• B. 4720 J
• C. 4960 J
• D. 4360 J

Hint:

Formula: \( H = I^2 R t \) gives heat in joules when current is in amperes, resistance in ohms, and time in seconds.

Answer 1

The Correct Option is A

The heat generated by current flowing through a resistor is calculated using the electrical power dissipation formula: H = I²Rt.

H = I²Rt

Here, H represents the heat in joules, I is the current in amperes, R is the resistance in ohms, and t is the time in seconds.

Provided:

• Current, I = 3 A
• Resistance, R = 4 Ω
• Time, t = 2 minutes, which converts to 120 seconds (2 × 60).

Plugging these values into the formula yields:

H = (3)² × 4 × 120

H = 9 × 4 × 120

H = 36 × 120

H = 4320 J

Consequently, the heat produced is 4320 Joules.