Magnetism & Matter — Previous-Year Questions

Q1. Ratio of axial to equatorial field of a short bar magnet at equal distance:

Q2. A bar magnet of length 2L has magnetic moment m. If broken at the middle:

Q3. Magnetic field along the axis of a short bar magnet at distance 0.1 m is B. At distance 0.2 m, field is:

Q4. Magnetic dipole moment of a current loop is:

Q5. Torque on a magnetic dipole in a uniform B is maximum when:

Q1. A short bar magnet has dipole moment 0.4 A·m². Equatorial field at 10 cm distance:

Q2. Same magnet — axial field at 10 cm:

Q3. Axial field of a short bar magnet at large r varies as:

Q4. Direction of equatorial field of a dipole is:

Q5. If two bar magnets of equal m are joined N-to-N along axis, resultant moment:

Q1. At a place, B_H = 0.3 G, B_V = 0.4 G. Total B and dip angle:

Q2. At the magnetic equator, dip angle is:

Q3. Earth's geomagnetic north pole is actually:

Q4. Origin of Earth's magnetic field is:

Q5. Declination is the angle between:

Q1. Susceptibility of a paramagnetic material is approximately:

Q2. Magnetization M is defined as:

Q3. Relation between μ_r and χ:

Q4. Inside an iron core (μ_r ≈ 1000) of a solenoid with H = 1000 A/m, B is:

Q5. For a diamagnetic material, susceptibility is:

Q1. Which material is ferromagnetic at room temperature?

Q2. Curie's law for paramagnetic susceptibility:

Q3. Above its Curie temperature, iron behaves as:

Q4. Diamagnetic susceptibility is approximately:

Q5. Ferromagnetism arises due to:

Q1. Area enclosed by the B-H hysteresis loop equals:

Q2. Coercivity H_c is:

Q3. Soft magnetic materials have:

Q4. When iron is heated above its Curie temperature, hysteresis loop:

Q5. Permanent magnets are made of: