A variable resistor is defined as?

A variable resistor is defined as?

• A. A resistor whose resistance can be changed by adjusting the portion of the resistor the current travels through
• B. A resistor with a fixed resistance
• C. A resistor that changes resistance with temperature
• D. A resistor used only in switching circuits

Answer: (A)

The meaning of a variable resistor is that its resistance can be changed by altering how much of the resistive material the current travels through. In devices like a rheostat or a potentiometer, moving a knob or slider shifts a contact along a resistive track, changing the effective length of the path the current takes. Since resistance is proportional to length for a uniform material, making the path longer increases resistance and making it shorter decreases resistance. This is why such a component is used to control current or voltage in a circuit. A resistor with fixed resistance doesn’t change, a resistor that varies with temperature would be a thermistor, and a resistor being used only in switching circuits isn’t what defines a variable resistor.

The meaning of a variable resistor is that its resistance can be changed by altering how much of the resistive material the current travels through. In devices like a rheostat or a potentiometer, moving a knob or slider shifts a contact along a resistive track, changing the effective length of the path the current takes. Since resistance is proportional to length for a uniform material, making the path longer increases resistance and making it shorter decreases resistance. This is why such a component is used to control current or voltage in a circuit. A resistor with fixed resistance doesn’t change, a resistor that varies with temperature would be a thermistor, and a resistor being used only in switching circuits isn’t what defines a variable resistor.