Automotive Electronics Practice Test

A series circuit has three resistors of 6 ohms each. How accurate is Technician A's statement that the source voltage is 12 volts?

1. Technician A only

2. Technician B only

3. Both Technicians A and B

4. Neither Technician A nor B

The correct answer is: Both Technicians A and B

In a series circuit, the total resistance is the sum of the individual resistances. For three resistors each having a resistance of 6 ohms, the total resistance would be calculated as follows: Total Resistance = 6 ohms + 6 ohms + 6 ohms = 18 ohms. Ohm's law states that Voltage (V) = Current (I) × Resistance (R). To determine the accuracy of Technician A's statement regarding the source voltage of 12 volts, we must consider the implications of the circuit's configuration. If the total resistance is 18 ohms and if we assume a source voltage of 12 volts, you can calculate the current flowing through the circuit using the formula: Current (I) = Voltage (V) / Resistance (R) = 12 volts / 18 ohms = 0.67 amps. Since this is a theoretical calculation based on the stated voltage and the total resistance, it's reasonable to conclude that the source voltage can indeed be 12 volts, depending on the current flowing through the circuit. Thus, if Technician B also has a supporting statement that aligns with the situation presented, both technicians could be providing accurate information, leading to the conclusion that both technicians can