Question

which device converts electric energy into mechanical energy?
a. an electromagnet
b. a motor
c. a generator
d. a transformer

Explanation:

• An electromagnet is a magnet in which the magnetic field is produced by an electric current. It mainly shows magnetic properties due to electricity but doesn't convert electric energy to mechanical energy in a general sense of mechanical work output like rotation etc.
• A motor works on the principle of electromagnetic induction. When an electric current is passed through a coil placed in a magnetic field, a torque is produced which causes the coil (and attached parts) to rotate. So, it converts electrical energy into mechanical energy (rotational motion).
• A generator is the opposite. It converts mechanical energy (like from a turbine) into electrical energy based on electromagnetic induction.
• A transformer is used to change the voltage level of an alternating - current (AC) supply. It works on the principle of mutual induction and doesn't convert electrical energy to mechanical energy.

Answer:

B. A motor