An electric motor uses electromagnetism for its working. An electromagnet is installed in it instead of a permanent magnet. A current carrying wire produces a magnetic field around it and this is the principle on which an electric motor works.
1. An electric motor converts ______ energy to ______ energy.
a. Mechanical,electric
b. Electric,mechanical
c. Electric,chemical
d. Mechanical, chemical
2. Identify where are electric motors used in the following?
a. Refrigerator
b. Electric crane
c. Rolling mills
d. All of the above
3. On which principle does an electric motor works?
a. Electromagnetism
b. Friction
c. Chemical energy
d. Muscular force
4. Which of the following are the parts of an electric motor?
a. Brushes
b. Armature coil
c. Both A and B
d. None of the above
5. What will happen if armature coil is removed from the electric motor?
a. More magnetic field will be produced
b. Efficiency of the motor will be doubled
c. Efficiency of the motor will be halved
d. The electric motor will not work