Which device is used to step up or step down AC voltages in power distribution?

Which device is used to step up or step down AC voltages in power distribution?

• A. Generator
• B. Electric Motor
• C. Galvonometer
• D. Transformer

Answer: (D)

Voltage transformation in power distribution is achieved with a transformer, which uses mutual induction between two coils wrapped around a shared magnetic core. When alternating current flows in the primary coil, it creates a changing magnetic flux that links to the secondary coil. The induced voltage on the secondary depends on the turns ratio of the coils: more turns on the secondary give a higher voltage (step-up), fewer turns give a lower voltage (step-down). This lets electricity be sent over long distances at high voltage to reduce losses and then stepped down for safe use at homes and businesses. Transformers require alternating current because a steady direct current would produce a constant magnetic field with no changing flux to induce voltage in the secondary. The other devices don’t transform voltage: a generator creates electrical energy, a galvanometer measures current, and a motor converts electrical energy into mechanical motion.

Voltage transformation in power distribution is achieved with a transformer, which uses mutual induction between two coils wrapped around a shared magnetic core. When alternating current flows in the primary coil, it creates a changing magnetic flux that links to the secondary coil. The induced voltage on the secondary depends on the turns ratio of the coils: more turns on the secondary give a higher voltage (step-up), fewer turns give a lower voltage (step-down). This lets electricity be sent over long distances at high voltage to reduce losses and then stepped down for safe use at homes and businesses. Transformers require alternating current because a steady direct current would produce a constant magnetic field with no changing flux to induce voltage in the secondary. The other devices don’t transform voltage: a generator creates electrical energy, a galvanometer measures current, and a motor converts electrical energy into mechanical motion.