A rheostat is a variable resistor with how many electrical connections?

A rheostat is a variable resistor with how many electrical connections?

• A. Three
• B. Two
• C. One
• D. Four

Answer: (B)

A rheostat is a two-terminal variable resistor. It changes the resistance by moving a contact along a resistive element, so only two electrical connections are needed—the end of the resistor and the movable contact (the wiper). This lets you vary current or voltage in a circuit by changing how much of the resistive path is in series. A three-terminal device would be a potentiometer, which uses all three terminals (two ends plus the wiper) to sense a voltage rather than to form a simple variable resistance. The other options don’t fit because one terminal wouldn’t complete a circuit, and four terminals aren’t standard for a rheostat.

A rheostat is a two-terminal variable resistor. It changes the resistance by moving a contact along a resistive element, so only two electrical connections are needed—the end of the resistor and the movable contact (the wiper). This lets you vary current or voltage in a circuit by changing how much of the resistive path is in series. A three-terminal device would be a potentiometer, which uses all three terminals (two ends plus the wiper) to sense a voltage rather than to form a simple variable resistance. The other options don’t fit because one terminal wouldn’t complete a circuit, and four terminals aren’t standard for a rheostat.