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Q 1. The function of commutator or slip ring in a motor is to
increase the current flowing through the coil
decrease the current flowing through the coil
change the direction of current through coil
change the direction of magnetic field
Q 2. By which instrument the presence of magnetic field can be determined?
Magnetic needle
Galvanometer  
Ammeter
Voltmeter
Q 3. A beam of alpha particles enters a chamber moving along the magnetic field. The force acting on them is
Maximum and perpendicular to the magnetic field
Maximum and along the magnetic field
Minimum and perpendicular to the magnetic field
Zero
Q 4. The potential difference maintained between the live wire and neutral wire in India is
240 V
220 V
440 V
420 V
Q 5. In Fleming's left-hand rule, which finger points in the direction of the magnetic field?
Thumb
Index finger
Middle finger
None of the above
Q 6. Strength of induced current is increased when
Number of turns in coil decreases
Magnetic field strength decreases
Magnetic field strength increases
Speed of conductor decreases
Q 7. A magnetic field existing around a magnet can be represented by magnetic field lines. Magnetic field lines always form:
open loops
closed loops
straight lines
Both closed loops and straight lines
Q 8. Small current in a circuit is detected by
Voltmeter
Solenoid
Fleming's left hand rule
Galvanometer
Q 9. An electric current flowing through a conductor produces
Magnetic field
Electric Field
Both electric and magnetic field
Electromagnetic field
Q 10. In an electric motor, which of the following supplies current to the coil through it?    
Brushes
Commutator
Switch
Axle
Q 11. A current through a horizontal power line flows in the east to west direction. The direction of magnetic field at a point directly below it is
from west to east
from North to South
from South to North
from East to West
Q 12. Select the correct statement
A stationary charged particle in a magnetic field experiences a magnetic force
Fleming's left hand rule is applicable only for negatively charged particles
The direction of velocity of charged particle is always perpendicular to the direction of magnetic field.
The direction of the force on current carrying conductor depends upon the direction of current and the direction of magnetic field.
Q 13. Which one of the following is the essential difference between an AC and DC generator?
AC generator has an electromagnet while a DC generator has a permanent magnet.
AC generator has slip rings while a DC generator has a commutator.
DC generator generates a higher voltage.
AC generator, generators a higher voltage.
Q 14. In electric generator, the direction of current in coil changes once every
One rotation
Two rotations
Half rotation
Three rotations
Q 15. The presence of magnetic field at a point can be detected by a
Compass needle
Solenoid
Current carrying wire
Strong magnet
Q 16. The magnetic field inside a current-carrying solenoid is
Zero
Increases as we move towards its ends
Decreases as we move towards its ends
Same at all points inside it
Q 17. If a charged particle does not experience any force in a magnetic field, then...
it is stationary.
it moves in the direction parallel to magnetic field
both (A) and (B)
it moves perpendicularly to the field.
Q 18. Which of the following metal is not attracted by a magnet?
Nickel
Cobalt
Steel
Silver
Q 19. An electron beam is moving from north to south and the magnetic field is directed downwards, then the beam deflected towards
West
East
North
South
Q 20. On & off switch is connected to?
Live wire
Neutral wire
Earth wire
Live and Neutral wire
Q 21. Induced current found to be highest when coil moves
Right angles to magnetic field
Parallel to magnetic field
  • At an angle of 45o
  • At an angle of 20o
Q 22. A current through a horizontal power line flows in East to West direction. The direction of magnetic field at a point directly above it is
From South to North
From North to South
From West to East
From East to West
Q 23. A cylindrical bar magnet is kept along the axis of a circular coil. If the magnet is rotated about the axis:
a current is induced in the coil as the magnetic flux linked with the coil changes.
a current is induced in the coil which after sometime reaches a saturated value.
no current is induced in the coil.
a current is induced in the coil and its value reduces gradually.
Q 24. A charged particle enters a uniform magnetic field, parallel to the field, its Kinetic energy:
Increases
Decreases
Remains constant
Becomes zero.
Q 25. The magnitude of force on current carrying conductor is the highest when the direction of current is
Parallel to the direction of magnetic field
At right angles to direction of magnetic field
  • At an angle of 45o to the direction of magnetic field
  • At an angle of 30o to the direction of magnetic field
Q 26. STATEMENT-1: Charges experience force when they move at right angles to a magnetic field. BECAUSE STATEMENT-2: A moving charge produces an electric field only. 
Statement 1 is true, statement 2 is true but, Statement 2 is correct explanation for statement 1.
Both Statement 1 and statement 2 are true but, Statement 2 is not the correct explanation for statement 1.
Statement 1 is true, statement 2 is false.
Statement 1 is false, statement 2 are true.
Q 27. In which direction does a freely suspended compass needle align itself?
North-east
North-South
East-West
North-west
Q 28. Fuse wire used in power circuit is of
5 A
220 A
15 A
10 A
Q 29. A vertical wire carries a current straight down. To the east of this wire, the magnetic field points:
southwards
downwards
eastwards
northwards
Q 30. The direction of current in a motor is changed with the help of which of the following options?
Half-circular ring
Brushes
Axle
Switch key
Q 31. Which material core is used in solenoid to make an electromagnet?
iron
Steel
Soft iron
Cobalt
Q 32. The law which is used to know the direction of magnetic field produced by a current carrying wire is
Fleming's right hand rule
Fleming's left hand rule
Right hand thumb rule
Left hand thumb rule
Q 33. At the time of short circuit, the current in the circuit ___________.
Increases
decreases 
remains the same 
increases in step
Q 34. The direction of force experienced by a current carrying conductor placed in a magnetic field can be found by
Fleming's right-hand rule
Right-hand thumb rule
Oersted's experiment
Fleming's left hand rule
Q 35. Which of the following property of a proton can change while it moves freely in a magnetic field?
mass
size
velocity
inertia
Q 36. Magnetic lines of force originate from the
South pole
North pole
Center point
Either north pole or south pole
Q 37. In the domestic electric circuits, the red coloured insulated copper wire is called
Earthing wire
Fuse wire
Live wire
Neutral wire
Q 38. Which of the following statements is false?
The magnetic field lines can cross each other.
The magnetic field lines form close loops.
In the region where the magnetic field lines are at a close distance from each other, there will be a strong magnetic field.
The direction of magnetic field line is from N to S.
Q 39. Fuse wire used in lighting circuit is of
10 A
2.5 A
5 A
15 A
Q 40. Which of the following statement concerning magnetic field is correct? (1) The part of a bar magnet, at which the magnetic field is the strongest, is called its pole.(2) A magnetic field is present near a compass needle. (3) There is no magnetic field inside a current-carrying solenoid.
(1) only
(2) only
(1) and (2) only
(2) and (3) only

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