10th Class Physics Chapter 10 Test19. Electromagnetism

Q1. Multiple choice questions (Attempt all · 10 × 1 = 10)

1. The induced current generated according to Lenz’s law always:
   1. Supports the motion of the magnet
   2. Opposes the motion of the magnet
   3. Stops the magnet
   4. Moves randomly
2. When the switch in relay is ON:
   1. Lamp remains OFF
   2. Current stops
   3. Lamp glows
   4. Armature is disconnected
3. The shaft on which the coil of an electric motor is mounted is called:
   1. Commutator
   2. Armature
   3. Brush
   4. Stator
4. In electromagnetic induction, current is induced as long as:
   1. Magnet is stationary
   2. Magnet is in motion
   3. Coil is broken
   4. Galvanometer is removed
5. The force on a conductor increases when:
   1. Current decreases
   2. Magnetic field strength increases
   3. Length of conductor decreases
   4. Both field and current are weak
6. The rule used to determine the direction of the magnetic field around a straight wire is:
   1. Left-hand rule
   2. Fleming’s right-hand rule
   3. Right-hand rule
   4. Lenz’s rule
7. The magnetic south pole of Earth’s magnet lies near the:
   1. Geographic South Pole
   2. Geographic North Pole
   3. Equator
   4. Rotation axis
8. Voltage in the secondary coil of a transformer does not depend upon:
   1. frequency of source
   2. primary voltage
   3. power losses
   4. turns ratio
9. The degree of deflection of electrons in an electric field depends on:
   1. Resistance
   2. Strength of electric field
   3. Mass of magnet
   4. Size of electrodes
10. The factor that affects induced e.m.f is:
    1. Length of coil only
    2. Number of turns of coil
    3. Thickness of wire only
    4. Type of galvanometer