Two bar magnets are held together tightly in a vibration magnetometer. When their like poles are together, they make \(20\) oscillations per minute and when their unlike poles are together, they make \(8\) oscillations per minute. The ratio of the magnetic dipole moments of two bar magnets is:
1. \(29:21\)
2. \(6:15\)
3. \(1:6\)
4. \(25:4\)

The magnetic susceptibility \(\chi\) of a diamagnetic material depends on absolute temperature \(T\) as:
1. \(\chi \propto T\)
2. \(\chi \propto \frac{1}{T}\)
3. \(\chi \propto T^0\)
4. \(\chi \propto \frac{1}{\sqrt{T}}\)

The magnetic lines of force inside a bar magnet are:

The material which is used to make permanent magnet has:

Which of the following is not dimensionless?
(where symbols stand for their usual meanings in magnetism)
1. \(\frac{I}{H}\)
2. \(\frac{B}{\mu_0H}\)
3. \(\mu_r\)
4. \(\frac{\mu_r B}{H}\)

The magnetic moment of a short dipole is \(100\) A-m². The magnetic induction in vacuum at \(1\) m from the dipole on the axis of the dipole is:
1. \(2\times10^{-5}~\text{T}\)
2. \(10^{-5}~\text{T}\)
3. \(2~\mu\text{T}\)
4. \(1~\mu\text{T}\)

The magnetic moment of a magnet \((10 ~\text{cm}\times 4~\text{cm}\times1~\text{cm})\) is \(4 ~\text{Am}^2\). Its intensity of magnetisation is:
1. \(10^{3}\) A/m
2. \(10^{2}\) A/m
3. \(10^{5}\) A/m
4. \(10^{4}\) A/m

S.I. unit of intensity of magnetization is:

A ferromagnetic material is placed in an external magnetic field. The magnetic domains:

Due to a small magnet, the intensity at a distance \(x\) in the end-on position is \(9~\text{gauss}\). What will be the intensity at a distance \(\frac{x}{2}\) on equatorial position?