Question

In a circuit, a current of \( 2 \, \text{A} \) flows through a resistor of resistance \( 5 \, \Omega \). Calculate the power dissipated in the resistor.

• A. \( 20 \, \text{W} \)
• B. \( 5 \, \text{W} \)
• C. \( 15 \, \text{W} \)
• D. \( 10 \, \text{W} \)

Hint:

Power dissipation in a resistor is proportional to the square of the current. Ensure to use the correct formula depending on what quantities are given in the problem.

Answer 1

The Correct Option is A

Given:

• Current: \( I = 2 \, \text{A} \)
• Resistance: \( R = 5 \, \Omega \)

Step 1: Use the formula for power dissipation in a resistor

The power dissipated in a resistor is given by: \[ P = I^2 R \] where: - \( P \) is the power dissipated, - \( I \) is the current, - \( R \) is the resistance.

Step 2: Substitute the given values into the formula

\[ P = (2 \, \text{A})^2 \times 5 \, \Omega \] \[ P = 4 \times 5 = 20 \, \text{W} \]

✅ Final Answer:

The power dissipated in the resistor is \( \boxed{20 \, \text{W}} \).