Automotive Electronics Practice Test

If the current flow through each of three resistors connected in parallel to a 12 volt battery is 4 amperes, what is the value of the resistors?

1. 1 ohm

2. 2 ohms

3. 3 ohms

4. 4 ohms

The correct answer is: 3 ohms

To determine the value of each resistor in this parallel circuit, it's essential to understand how voltage, current, and resistance relate to each other through Ohm's Law, which states that voltage (V) equals current (I) times resistance (R), or V = I × R. In this scenario, the voltage supplied by the battery is 12 volts, and the current flowing through each of the three resistors is 4 amperes. Based on Ohm's Law, we can rearrange the formula to find the resistance: R = V/I. Plugging in the values for one of the resistors: R = 12 volts / 4 amperes = 3 ohms. Since all three resistors are connected in parallel and each has the same current flowing through it, they all must have the same resistance value. Therefore, each resistor in this case has a value of 3 ohms. This demonstrates the correct understanding of how parallel circuits operate, as the voltage across each resistor is the same when connected to the same supply voltage, while the current may vary based on each resistor's resistance.