What electromagnetic device produces rotary motion?

• A. Transformer
• B. Motor
• C. Generator
• D. Relay

Answer: (B)

Electric motors are designed to turn electrical energy into rotational mechanical energy. When current flows through windings placed in a magnetic field, forces act on those conductors and create torque on the rotor. A commutator or electronic drive reverses the current as the rotor turns, ensuring the torque keeps rotating in the same direction. That continuous torque produces sustained rotary motion, which is why motors are used to drive wheels, fans, drills, and many other devices.

Transformers transfer energy between circuits through changing magnetic flux and have no moving parts, so they don’t produce motion. Generators do the opposite, converting mechanical energy into electrical energy. Relays use an electromagnet to move contacts, typically producing linear motion to open or close circuits, not continuous rotation.