Question:

A circuit consists of a power source with a potential difference of 12 V, a resistor with a resistance of 4 Ω, and an ammeter connected in series. The ammeter reads a current of 2 A. Calculate the power dissipated by the resistor.

Answer:

To calculate the power dissipated by the resistor, we will use the formula:

Power (P) = Current (I)² * Resistance (R)

Given: Potential difference (V) = 12 V Resistance (R) = 4 Ω Current (I) = 2 A

Substituting the given values into the formula, we have:

P = (2 A)² * 4 Ω

To solve this, we can follow these steps:

1. Calculate the square of the current:

(2 A)² = 4 A²

2. Substitute the squared current into the formula:

P = 4 A² * 4 Ω

3. Simplify the expression:

P = 16 A²Ω

Hence, the power dissipated by the resistor is 16 A²Ω.

Note: The unit A²Ω is equivalent to a watt (W), which is the SI unit of power.