The basic magnetization curve for a ferromagnetic material is shown in the figure. Then, the value of relative permeability is highest for the point :

 

 

1. P         

2. Q

3. R         

4. S

A superconductor exhibits perfect :

1. Ferrimagnetism              

2. Ferromagnetism

3. Paramagnetism              

4. Diamagnetism

Among the following properties describing diamagnetism identify  the property that is wrongly stated

1. Diamagnetic material do not have permanent magnetic moment

2. Diamagnetism is explained in terms of electromagnetic induction

3. Diamagnetic materials have a small positive susceptibility

4. The magnetic moment of individual electrons neutralize each other

If a magnet is suspended at an angle 30^o to the magnetic meridian, it makes an angle of 45^o with the horizontal. The real dip is

1. ${\tan }^{-1}\left(\frac{\sqrt{3}}{2}\right)$

2. ${\tan }^{-1}\left(\sqrt{3}\right)$

3. ${\tan }^{-1}\left(\sqrt{\frac{3}{2}}\right)$

4. ${\tan }^{-1}\left(\frac{2}{\sqrt{3}}\right)$

The true value of angle of dip at a place is 60^o, the apparent dip in a plane inclined at an angle of 30^o with magnetic meridian is

1. ${\tan }^{-1}\left(\frac{1}{2}\right)$

2. ${\tan }^{-1}\left(2\right)$

3. ${\tan }^{-1}\left(\frac{2}{3}\right)$

4. None of these

Two magnets \(A\) and \(B\) are identical and these are arranged as shown in the figure. Their length is negligible in comparison to the separation between them. A magnetic needle is placed between the magnets at point \(P\) which gets deflected through an angle \(\theta\) under the influence of magnets. The ratio of distance \(d_1\) and \(d_2\) will be:
   
1. \((2\tan\theta)^{\frac{1}{3}}\)
2. \((2\tan\theta)^{\frac{-1}{3}}\)
3. \((2\cot\theta)^{\frac{1}{3}}\)
4. \((2\cot\theta)^{\frac{-1}{3}}\)

Two short magnets of equal dipole moments M are fastened perpendicularly at their centres (figure). The magnitude of the magnetic field at a distance d from the centre on the bisector of the right angle is :

1. $\frac{{\mu }_0}{4\mathrm{\pi }}<mspace\; width="1em"></mspace>\frac{M}{d^3}<mspace\; width="1em"></mspace>$

2. $\frac{{\mu }_0}{4\mathrm{\pi }}<mspace\; width="1em"></mspace>\frac{M\sqrt{2}}{d^3}$

3. $\frac{{\mu }_0}{4\mathrm{\pi }}<mspace\; width="1em"></mspace>\frac{2\sqrt{2}M}{d^3}$

4. $\frac{{\mu }_0}{4\mathrm{\pi }}<mspace\; width="1em"></mspace>\frac{2M}{d^3}$

Each atom of an iron bar\(\) (5 cm × 1 cm × 1 cm) has a magnetic moment \(1 . 8 \times 10^{- 23} A m^{2}\). Knowing that the density of iron is \(7 . 78 \times 10^{3} k g m^{- 3}\) atomic weight is 56 and Avogadro's  number is \(6 . 02 \times 10^{23}\) the magnetic moment of the bar in the state of magnetic saturation will be:

1. 4.75 Am²                 

2. 5.74 Am²

3. 7.54 Am²                 

4. 75.4 Am²

A dip needle lies initially in the magnetic meridian when it shows an angle of dip $\theta$ at a place. The dip circle is rotated through an angle x in the horizontal plane and then it shows an angle of dip $\theta \text{'}$. Then $\frac{\tan <mspace\; width="1em"></mspace>\theta \text{'}}{\tan <mspace\; width="1em"></mspace>\theta }$ is

1. 1/cos x

2. 1/sin x

3. 1/tan x

4. cos x

The variation of magnetic susceptibility $\left(\chi \right)$ with temperature for a diamagnetic substance is best represented by

1. 

2. 

3. 

4.