A circuit that uses resistors to produce a voltage that is lower than the source voltage is called a __________.

• A. Step-down network
• B. Voltage divider
• C. Voltage regulator
• D. Potential divider

Answer: (B)

A circuit that uses resistors in series to produce a smaller output voltage from a higher input voltage is called a voltage divider. This works because the resistors share the input voltage in proportion to their resistance, so the voltage across the chosen resistor (or combination) is a fraction of Vin. For two resistors in series, Vout across the bottom resistor is Vin times Rbottom divided by (Rtop + Rbottom). For example, with Vin = 9V, Rtop = 2kΩ and Rbottom = 3kΩ, Vout = 9V × (3k/(2k+3k)) = 5.4V. This concept is fundamental for biasing circuits, sensor circuits, and creating reference levels, though note that the output depends on the load; if a heavy load is connected, the voltage can shift unless the divider is buffered or followed by a regulator. The term “potential divider” is sometimes used, but the standard name for this resistor-based arrangement is a voltage divider.