1. The region around a magnet where magnetic force can be felt is called:
A) Magnetic field
B) Electric field
C) Gravitational field
D) Nuclear field
2. The SI unit of magnetic field is:
A) Volt
B) Tesla
C) Ohm
D) Watt
3. Like poles of magnets:
A) Attract
B) Neutralize
C) Repel
D) Disappear
4. Unlike poles of magnets:
A) Repel
B) Become neutral
C) Rotate only
D) Attract
5. The magnetic field lines emerge from:
A) North pole
B) South pole
C) Center of magnet
D) Neutral region
6. Magnetic field lines enter into:
A) North pole
B) South pole
C) Center of Earth
D) Neutral body
7. Magnetic field lines never:
A) Form loops
B) Show direction
C) Intersect each other
D) Curve
8. The magnetic effect of electric current was discovered by:
A) Newton
B) Faraday
C) Maxwell
D) Oersted
9. The direction of magnetic field around a straight conductor is determined by:
A) Right hand grip rule
B) Fleming’s left hand rule
C) Ohm’s law
D) Joule’s law
10. An electromagnet is usually made by winding wire around:
A) Copper core
B) Soft iron core
C) Aluminum rod
D) Plastic rod
11. Soft iron is used in electromagnets because it:
A) Retains magnetism permanently
B) Is non-magnetic
C) Gains and loses magnetism easily
D) Is very hard
12. A device that converts electrical energy into mechanical energy is:
A) Generator
B) Transformer
C) Galvanometer
D) Electric motor
13. Fleming’s left hand rule is used for:
A) Electric motor
B) Generator
C) Transformer
D) Battery
14. A generator converts mechanical energy into:
A) Heat energy
B) Electrical energy
C) Magnetic energy
D) Chemical energy
15. Fleming’s right hand rule is used for:
A) Electric motor
B) Electroscope
C) Generator
D) Capacitor
16. Electromagnetic induction was discovered by:
A) Newton
B) Joule
C) Oersted
D) Faraday
17. The induced current produced in a conductor depends upon:
A) Change in magnetic flux
B) Mass of conductor
C) Color of wire
D) Resistance only
18. The unit of magnetic flux is:
A) Tesla
B) Weber
C) Volt
D) Henry
19. A transformer works on the principle of:
A) Heating effect
B) Chemical effect
C) Electromagnetic induction
D) Electrostatics
20. A transformer can operate only on:
A) Alternating current
B) Direct current
C) Static current
D) Chemical current
21. The transformer that increases voltage is called:
A) Step-down transformer
B) Power transformer
C) Isolation transformer
D) Step-up transformer
22. The transformer that decreases voltage is called:
A) Step-up transformer
B) Step-down transformer
C) Current transformer
D) Magnetic transformer
23. The core of transformer is usually made of:
A) Soft iron
B) Steel
C) Copper
D) Aluminum
24. The part of motor that reverses current direction is:
A) Coil
B) Magnet
C) Split ring commutator
D) Brush
25. The device used to detect weak electric current is:
A) Ammeter
B) Voltmeter
C) Transformer
D) Galvanometer
26. In a generator, mechanical energy is converted into electrical energy due to:
A) Heating effect
B) Electromagnetic induction
C) Resistance
D) Friction
27. The direction of induced current is determined by:
A) Fleming’s right hand rule
B) Fleming’s left hand rule
C) Ohm’s law
D) Coulomb’s law
28. Magnetic field strength is maximum at the:
A) Center of magnet
B) Neutral region
C) Poles of magnet
D) Middle of wire
29. The temporary magnet produced by current is called:
A) Permanent magnet
B) Bar magnet
C) Natural magnet
D) Electromagnet
30. The magnetic field around a straight conductor carrying current is:
A) Circular
B) Linear
C) Elliptical
D) Random
31. The stronger magnetic field in electromagnet can be produced by:
A) Reducing turns of coil
B) Increasing current
C) Removing iron core
D) Increasing resistance
32. The SI unit of inductance is:
A) Weber
B) Tesla
C) Henry
D) Volt
33. The current produced by a DC generator is:
A) Alternating
B) Oscillating
C) Variable
D) Direct current
34. AC generator produces:
A) Alternating current
B) Direct current
C) Static current
D) Chemical current
35. The magnetic field of Earth behaves like that of a:
A) Circular magnet
B) Bar magnet
C) Horseshoe magnet
D) Ring magnet
36. The compass needle always points in:
A) East-West direction
B) Vertical direction
C) North-South direction
D) Random direction
37. The force on a current carrying conductor in magnetic field is maximum when conductor is:
A) Perpendicular to magnetic field
B) Parallel to magnetic field
C) Stationary
D) Circular
38. The magnetic material commonly used in permanent magnets is:
A) Copper
B) Aluminum
C) Soft iron
D) Steel
39. In an electric bell, the hammer vibrates due to:
A) Gravity
B) Electromagnet
C) Friction
D) Heat
40. The magnetic field inside a solenoid is:
A) Uniform
B) Zero
C) Circular
D) Weak
41. Which of the following uses electromagnet?
A) Prism
B) Lens
C) Electric bell
D) Thermometer
42. The device used to increase or decrease AC voltage is:
A) Generator
B) Motor
C) Ammeter
D) Transformer
43. The primary coil of transformer is connected to:
A) Output supply
B) Input supply
C) Earth wire
D) Neutral wire
44. The secondary coil of transformer is connected to:
A) Output circuit
B) Battery
C) Earth wire
D) Switch only
45. Electromagnetic induction is the production of:
A) Heat
B) Magnetism
C) Induced current
D) Resistance
46. The magnetic field strength around a conductor increases when current:
A) Stops
B) Decreases
C) Becomes zero
D) Increases
47. The rotating part of an electric motor is called:
A) Armature
B) Core
C) Magnet
D) Brush
48. The stationary part of a motor or generator is called:
A) Rotor
B) Stator
C) Armature
D) Coil
49. The efficiency of transformer is usually:
A) Very low
B) 25%
C) High
D) Zero
50. The magnetic field around a solenoid resembles that of a:
A) Bar magnet
B) Circular ring
C) Plane mirror
D) Prism