Question

which device is used to increase or decrease the voltage of an alternating current? a. a commutator b. a transformer c. a generator d. a motor

Explanation:

• A commutator is used to convert alternating current to direct current in a DC motor or generator.
• A transformer works on the principle of electromagnetic induction and can increase (step - up) or decrease (step - down) the voltage of an alternating current.
• A generator is a device that converts mechanical energy into electrical energy (either AC or DC depending on the type).
• A motor is a device that converts electrical energy into mechanical energy.

Answer:

B. A transformer