Use Ohm's law to determine the potential difference across the $3 \Omega$ resistor in the circuit shown in the following diagram when key is closed:

Hint

Use Ohm's law to calculate the potential difference across the $3 \Omega$ resistor.

Quick oral answer

To determine the potential difference across the $3 \Omega$ resistor, we need to apply Ohm's law, which states that the potential difference (V) across a conductor is equal to the product of the current (I) flowing through it and its resistance (R). In this case, the current flowing through the $3 \Omega$ resistor is $2$ A, and the resistance is $3 \Omega$. Therefore, the potential difference across the $3 \Omega$ resistor is $V = I \times R = 2 \times 3 = 6$ V.