A component used to limit current in a circuit by converting electrical energy to heat is called a

A component used to limit current in a circuit by converting electrical energy to heat is called a

• A. Resistor
• B. Capacitor
• C. Inductor
• D. Transformer

Answer: (A)

The idea being tested is how a component can limit current by turning electrical energy into heat. A resistor does this because it resists the flow of current. When current passes through, energy is dissipated as heat, following the relationships P = I^2R or P = V^2/R. This means for a given voltage, higher resistance reduces current and converts more of the electrical energy into heat, effectively limiting the current in the circuit. For example, with a 9-volt source and a 10-ohm resistor, the current is 0.9 A and the resistor dissipates about 8.1 watts as heat. In contrast, a capacitor stores energy in an electric field and only briefly conducts while charging, after which it stops dissipating energy as heat. An inductor stores energy in a magnetic field and resists changes in current rather than converting most of it to heat. A transformer transfers energy through magnetic induction and does not primarily dissipate energy as heat. So the component that limits current by converting electrical energy to heat is the resistor.

The idea being tested is how a component can limit current by turning electrical energy into heat. A resistor does this because it resists the flow of current. When current passes through, energy is dissipated as heat, following the relationships P = I^2R or P = V^2/R. This means for a given voltage, higher resistance reduces current and converts more of the electrical energy into heat, effectively limiting the current in the circuit. For example, with a 9-volt source and a 10-ohm resistor, the current is 0.9 A and the resistor dissipates about 8.1 watts as heat. In contrast, a capacitor stores energy in an electric field and only briefly conducts while charging, after which it stops dissipating energy as heat. An inductor stores energy in a magnetic field and resists changes in current rather than converting most of it to heat. A transformer transfers energy through magnetic induction and does not primarily dissipate energy as heat. So the component that limits current by converting electrical energy to heat is the resistor.