How many terminals (leads) does a standard potentiometer provide for connection in circuits such as voltage dividers and rheostats?
-
A1
-
B2
-
C3
-
D4
Answer
Correct Answer: 3
Explanation
Introduction / Context:A potentiometer is a three-terminal variable resistor used either as a voltage divider (three terminals used) or as a rheostat (two terminals used). Understanding its terminal count and usage modes is foundational in analog interfaces and control circuits.
Given Data / Assumptions:
- Standard rotary or slide potentiometer.
- Two end terminals connect to the ends of the resistive element; the third is the movable wiper.
Concept / Approach:With three terminals, a potentiometer can divide an applied voltage to produce an adjustable fraction at the wiper. If used as a rheostat, only the wiper and one end terminal are connected externally, but the device still physically provides three leads.
Step-by-Step Solution:Identify terminals: End A, Wiper, End B.Voltage divider mode: use all three (A–W–B).Rheostat mode: use two (W + A or W + B) while the third remains unused or tied to the wiper for noise reduction.
Verification / Alternative check:Datasheets label pins 1–2–3 or A–W–B and show both usage modes. The physical count is consistently three for standard potentiometers.
Why Other Options Are Wrong:
- 1 or 2: Too few for full divider functionality; two are used only in rheostat configuration.
- 4: Specialized multi-gang or dual pots have more terminals, but a single potentiometer section has three.
Common Pitfalls:
- Confusing the number of connected leads in a given application with the number of available terminals on the device.
- Miswiring the wiper and end terminals, which reverses the control direction.
Final Answer:3