NEET

A short bar magnet of magnetic moment 0.4 J T^–1 is placed in a uniform magnetic field of 0.16 T. The magnet is in stable equilibrium when the potential energy is

– 0.64 J
zero
– 0.082 J
0.064 J

Solution

For stable equilibrium

U = –MB = – (0.4) (0.16) = – 0.064 J

Isogonic lines on magnetic map represent lines of

zero declination
equal declination
equal dip
equal horizontal field

In the hysterisis cycle, the value of H needed to make the intensity of magnetisation zero is called

Retentivity
Coercive force
Lorentz force
None of the above

A frog can jump higher than normal in a magnetic field because the tissues of a frog are

paramagnetic
diamagnetic
ferro magnetic
antiferro magnetic

Which of the following is diamagnetism?

Aluminium
Quartz
Nickel
Bismuth

Solution

Bi(Bismuth) is diamagnetic.

If a magnetic substance is kept in a magnetic field then which of the following substance is thrown out?

Paramagnetic
Ferromagnetic
Diamagnetic
Antiferromagnetic

Solution

If a magnetic substance is placed in a magnetic field then substances are repelled by magnet. This shows diamagnetic property.

If horizontal and vertical components of earths magnetic field are equal, then angle of dip is

60°
45°
30°
90°

Solution

The moment of a magnet (15 cm × 2 cm × 1 cm) is 1.2 A-m².What is its intensity of magnetisation?

4 × 10⁴A m^–1
2 × 10⁴A m^–1
10⁴A m^–1
None of these

Solution

The relative permeability of a medium is 0.075. What is its magnetic susceptibility?

0.925
– 0.925
1.075
–1.075

Solution

From μ_rr = 1 + x_m;

Magnetic suscaptibility, x_m = μ_rr - 1

x_m =0.075 - 1 = -0.925.

If relative permeability of iron is 2000. Its absolute permeability in S.I. units is

8π × 10^–4
8π× 10^–3
800/π
8π × 10⁹/π

Solution

μ = μ₀μ_r = (4π × 10^-7) × 2000 = 8π × 10^–4 S.I. units

UnAttempted

0

Attempted

0

Correct

0

Wrong

0

Complete

Attempted

Correct

UnAttempted

Wrong