Liquid oxygen remains suspended between two pole faces of a magnet because it is

• diamagnetic

• paramagnetic

• ferromagnetic

• antiferromagnetic

82.

Assertion:  A famous painting was painted by not using brush strokes in the usual manner, but rather a myriad of small color dots. In this painting the color you see at any given place on the painting changes as you move away.

Reason: The angular seperation of adjacent dots changes with the distance from the painting.

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false

• If both assertion and reason are false

A frog can be levitated in a magnetic field produced by a current in a vertical solenoid placed below the frog. This is possible because the body of the frog behaves as 

• paramagnetic

• diamagnetic

• ferromagnetic

• antiferromagnetic

The magnetic needle of a tangent galvanometer is deflected at an angle 30° due to a magnet. The horizontal component of earth's magnetic field 0.34 x 10^-4 T is along the plane of the coil. The magnetic intensity is

• 1.96 × 10^-4 T

• 1.96 × 10⁴ T

• 1.96 × 10^-5 T

• 1.96 × 10⁵ T

Velocity of light is equal to

• $\sqrt{{\mathrm{\epsilon }}_{\mathrm{o}} {\mathrm{\mu }}_{\mathrm{o}}}$

• $\sqrt{\raisebox{1ex}{${\mathrm{\epsilon }}_{\mathrm{o}}$}\!\left/ \!\raisebox{-1ex}{${\mathrm{\mu }}_{\mathrm{o}}$}\right.}$

• ε_o/ μ_o

• $\sqrt{\frac{1}{{\mathrm{\epsilon }}_{\mathrm{o}} {\mathrm{\mu }}_{\mathrm{o}}}}$

Assertion:  Faraday's laws are consequences of conservation of energy. 

Reason: In a purely resistive A.C. circuit, the current lags behind the e.m.f. in phase.

• If both the assertion and reason are true and reason is a correct explanation of the assertion.

• If both assertion and reason are true but assertion is not a correct explanation of the assertion.

• If the assertion is true but the reason is false.

• If both assertion and reason are false.

A copper rod is suspended in a non-homogeneous magnetic field region. The rod when in equilibrium will align itself

• in the region where magnetic field is strongest

• in the region where magnetic field is weakest and parallel to direction of magnetic field there

• in the direction in which it was originally suspended

• in the region where magnetic field is weakest and perpendicular to the direction of magnetic field there

Iron is ferromagnetic

• at all temperatures

• at NTP only

• above 770°C

• below 770°C

Relative permeability of iron is 5500, then its magnetic susceptibility will be

• 5500 × 10⁷

• 5500 × 10^-7

• 5501

• 5499

In the unmagnetized state magnetic domains of a magnetic substance are oriented at

• 60°

• 90°

• randomly

• 150°