What can occur when an inductor resists a change in current and the circuit is opened?

What can occur when an inductor resists a change in current and the circuit is opened?

• A. Spark
• B. Voltage spike across the resistor
• C. Heat buildup
• D. Ground fault

Answer: (A)

When an inductor experiences a change in current, it resists that change by releasing its stored magnetic energy as a voltage. If the circuit is opened, the current tries to continue, causing the inductor to generate a high voltage to keep the current going. This sudden voltage can ionize the air between the open contacts and create a spark (an arc) as the circuit tries to find a path to continue the current. Heat buildup would require sustained current flow, which isn’t the immediate effect when the circuit is opened. A ground fault involves current taking an unintended path to ground, which isn’t inherently implied by simply opening an inductive circuit. A voltage spike across a resistor could occur in some transient scenarios, but the most direct and observable outcome of opening an inductive circuit is the spark caused by the collapsing magnetic field.

When an inductor experiences a change in current, it resists that change by releasing its stored magnetic energy as a voltage. If the circuit is opened, the current tries to continue, causing the inductor to generate a high voltage to keep the current going. This sudden voltage can ionize the air between the open contacts and create a spark (an arc) as the circuit tries to find a path to continue the current.

Heat buildup would require sustained current flow, which isn’t the immediate effect when the circuit is opened. A ground fault involves current taking an unintended path to ground, which isn’t inherently implied by simply opening an inductive circuit. A voltage spike across a resistor could occur in some transient scenarios, but the most direct and observable outcome of opening an inductive circuit is the spark caused by the collapsing magnetic field.