The voltage level in alternating current can easily be changed how?

The voltage level in alternating current can easily be changed how?

• A. using a transformer
• B. by adjusting frequency
• C. by changing resistance
• D. by varying duty cycle

Answer: (A)

AC voltage can be changed easily with a transformer. A transformer uses two coils on a shared magnetic core. When AC flows in the primary, it continually changes the magnetic flux, and that changing flux induces a voltage in the secondary coil. The amount of voltage induced depends on the turns ratio between the primary and secondary windings, so you can step the voltage up or down simply by adjusting how many turns the secondary has relative to the primary. This only works with AC because a changing magnetic field is needed to induce voltage; DC would quickly saturate the core and stop inducing a new voltage. Changing frequency, resistance, or duty cycle doesn’t provide the same straightforward, reliable way to set the voltage level.

AC voltage can be changed easily with a transformer. A transformer uses two coils on a shared magnetic core. When AC flows in the primary, it continually changes the magnetic flux, and that changing flux induces a voltage in the secondary coil. The amount of voltage induced depends on the turns ratio between the primary and secondary windings, so you can step the voltage up or down simply by adjusting how many turns the secondary has relative to the primary. This only works with AC because a changing magnetic field is needed to induce voltage; DC would quickly saturate the core and stop inducing a new voltage. Changing frequency, resistance, or duty cycle doesn’t provide the same straightforward, reliable way to set the voltage level.