Q1 Magnetic field intensity at a point on the axial line of the magnet various with distance 'r' of the point from the center of the bar magnet as

• (a) r^{1}
• (b) r^{2}
• (c) r^{-1}
• (d) r^{-3}

• (d) r^{-3}

Q2 Suppose magnetic field intensity at a distance r from the center of a short bar magnet on the axial live is B. Then magnetic field intensity at a distance r from the bisector of the bar magnet is.

• a) B
• b) 2B
• c) B/2
• d) None of these

• c) B/2

• a) m/l
• b) 2M/л
• c) m
• d) M

• b) 2M/л

Q4 If magnetic length of a bar magnet is 'x' and the geometrical length of the bar magnet is 'y', then:

• a) x = y
• b) x > y
• c) x < y
• d) None of these

• c) x < y

Q5 SI units of magnetic dipole moment of a bar magnet are

• a) Am^{2}
• b) Am^{-1}
• c) Am^{-2}
• d) A^{-1}m

• a) Am^{2}

• a) F
• b) F/4
• c) 2F
• d) F/2

• a) F

• a) True
• b) False

• a) True

Q8 What is the net magnetic flux through a closed surface?

• a) Positive
• b) Negative
• c) Zero
• d) Depends on the nature of the surface

• c) Zero

Q9.  ‘X’ is the product of the pole strength of either magnetic pole and the magnetic length of the magnetic dipole. Identify X.

• a) Magnetic dipole
• b) Magnetic dipole moment
• c) Magnetic pole strength
• d) Magnetic dipole length

• b) Magnetic dipole moment

Q10 What is the torque exerted by a bar magnet on itself due to its field?

• a) Maximum
• b) Zero
• c) Minimum
• d) Depends on the direction of the magnetic field

• b) Zero,
• A bar magnet does not exert a force or torque on itself due to its field. But an element of a current-carrying conductor experiences forces due to another element of the conductor. So, the torque exerted by a bar magnet on itself is zero.