Automotive Electronics Practice Test

Four resistors are connected to a 12 volt battery in series. Which technician is correct about where the greatest voltage drop occurs?

1. Technician A only

2. Technician B only

3. Both Technicians A and B

4. Neither Technician A nor B

The correct answer is: Technician B only

In a series circuit, the total voltage of the power supply is divided among the components based on their resistance values. Ohm's Law, expressed as V = I * R, indicates that each resistor experiences a voltage drop proportional to its resistance. Thus, the resistor with the highest resistance will encounter the greatest voltage drop. Technician B's assertion that the largest voltage drop occurs across the resistor with the highest resistance is accurate because, in a series arrangement, the voltage drop across each resistor can vary, but the one with the maximum resistance will result in the maximum drop. This principle is fundamental to understanding how voltage behaves in series circuits and is critical for analyzing and designing electronic circuits, ensuring that components operate within their specified voltage ranges. On the other hand, Technician A's claim may not consider the relationship between resistance and voltage drop in series circuits, which leads to the conclusion that only Technician B presents the correct understanding of where the greatest voltage drop occurs.