NTSE SAT Physics Magnetism MCQs

Question: A bar magnet has been cut equally length wise and width wise to give four equal pieces. The pole strength of each piece as compared to the pole strength of original bar magnet is :

• a) Same
• b)

  

• c)

  

• d)

  

Answer:

Question: The direction of magnetic lines of force of a bar magnet is :

• a) From south pole to north pole
• b) From north pole to south pole
• c) Across the bar magnet
• d) From south pole to north pole inside the magnet and from north pole to south pole outside the magnet.

Answer: Across the bar magnet

Question: A copper wire ring is suspended vertically, on bringing a bar magnet towards the ring, then ring will :

• a) Move towards magnet
• b) Move away from magnet
• c) Remains stationary
• d) Rotate with respect to suspensions fiber

Answer: Move away from magnet

Question: The radius of a circular wire is 0.5 and the current is 10 amp. What is the magnitude of magnetic field at the center of the circular wire ?

• a) 12.57 × 10^-6 T 
• b) 12.57 × 10⁺⁵ T 
• c) 12.57 10^-4 T
• d) 12.57 × 10^-3 T

Answer: 12.57 × 10^-6 T 

Question: A proton is moving with velocity 104 m/s parallel to the magnetic field of intensity 5 tesla. The force on the proton is :

• a) 8 × 10^-15 N 
• b) 104 N
• c) 1.6 × 10^-19 N  
• d) Zero

Answer: Zero

Question: The pole faces of a permanent magnet as shown in the figure. A wire of length 4 cm, crying a current of 10A is placed in the central region, where the magnetic field is 0.2 T. The magnitude of the force on the wire is :   

• a) 0.8 N
• b) 0.08 N
• c) 8 N
• d) Zero

Answer: 0.08 N

Question: Which of the following shows that the earth behaves as a magnet ?

• a) Repulsion between like poles.
• b) Attraction between like poles.
• c) Existence of null points in the magnetic field of a bar magnet.
• d) Nonexistence of monopoles.

Answer: Existence of null points in the magnetic field of a bar magnet.

Question: Which among the following gets strongly attracted by magnets ?

• a) Diamagnetic substances
• b) Paramagnetic substances
• c) Ferromagnetic substances
• d) All of the above

Answer: Ferromagnetic substances

Question: Soft iron is used to manufacture electromagnets because their :

• a) Coercive force is high
• b) Retentive is high
• c) Area of hysteresis curve is large
• d) Magnetic saturation limit is high & retentive and coercive force are small.

Answer: Retentive is high

Question: A coil is placed in a constant magnetic field. The plane of the coil is parallel to magnetic field as shown in figure then the flux passing through coil will be :

• a) BA
• b)

  

• c) Zero
• d) Infinity

Answer: Zero

Question: Permanent magnets are made up of :

• a) Soft iron
• b) Aluminum
• c) Alnico
• d) Copper

Answer: Alnico

Question: Two parallel wire carrying current in opposite direction :

• a) Attract each other
• b) Repel each other
• c) No force act between them
• d) None of them

Answer: Repel each other

Question: Force acting on a current crying conductor placed perpendicular to the magnetic filled is :

• a) Maximum
• b) Zero
• c) Zero or maximum
• d) None of these

Answer: Maximum

Question: A wire of length 1m through which a current of 0.2 A is flowing. It is placed in a magnetic field of 0.4T. The maximum magnetic force on the wire is.

• a) 0.8 N
• b) 0.08 N
• c) 8 N
• d) None of these

Answer: 0.08 N

Question: The magnetic field intensity produced due to a current carrying coil is maximum at :

• a) Any point
• b) The center of the coil
• c) Any point lying on the axis of the coil
• d) Points lying between center of the coil and is circumference

Answer: The center of the coil

Question: Force acting on a stationary charge Q in the magnetic field B is :

• a) BQV
• b) BV/Q
• c) Zero
• d) BQ/V

Answer: Zero

Question: If a magnet is cut in four equal parts then joined together with quick fix, the resulting bar magnet will behave as :

• a) Four bar magnet
• b) Four normal iron bars
• c) A normal bar magnet
• d) A normal iron bar

Answer: A normal bar magnet

Question: Permanent magnets are made up of :

• a) Soft iron
• b) Aluminum
• c) Alnico
• d) Copper

Answer: Alnico

Question: Force acting on a current crying conductor placed perpendicular to the magnetic filled is :

• a) Maximum
• b) Zero
• c) Zero or maximum
• d) None of these

Answer: Maximum

Question: Force acting on a stationary charge Q in the magnetic field B is :

• a) BQV
• b) BV/Q
• c) Zero
• d) BQ/V

Answer: Zero