The angle of dip is ${\theta }_1$ on a given meridian which is at an angle $\theta$ with the magnetic meridian. If ${\theta }_2$ is the angle of dip on another meridian which is perpendicular to the first meridian, then $\mathrm{\theta }, {\mathrm{\theta }}_{1 }\mathrm{and} {\mathrm{\theta }}_2$ are related as :

1. cot²$\theta$ = cot²${\theta }_1$+cot²${\theta }_2$

2. tan²$\theta$ = tan²${\theta }_1$+tan²${\theta }_2$

3. tan$\theta$ = $\frac{\tan {\theta }_1}{\tan {\theta }_2}$

4. tan$\theta$ = tan${\theta }_1$ + tan${\theta }_2$

The magnetic susceptibility χ of a ferromagnetic material varies with temperature, as:

1.		2.
3.		4.

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 unit of intensity of the magnetising field is :

1.$\frac{N}{Wb}$

2. $\frac{J}{m^3\times tesla}$

3. $\frac{J}{m\times Wb}$

4. All of these

If at any place, the angle of dip is  $\theta$ and magnetic latitude is $\lambda$, then (assume that the axis of earth's magnetic moment coincides with axis of rotation of the earth)

1. $\theta$ =  $\lambda$

2. tan$\theta$ = cos$\lambda$

3. tan$\theta$.cot$\lambda$ = 2

4. tan$\theta$.cot$\lambda$ =$\frac{1}{2}$

If A is the area of the graph of the intensity of magnetisation in ferromagnetic material versus magnetising field intensity, V is the volume of the magnetic sample and n is the frequency of alternating magnetic field, then the rate of hysteresis loss in the substance is 

1. A

2. AVn

3. $\frac{AV}{n}$

4. $\frac{A}{nV}$

A magnet is oscillating with the time period 'T' in a vertical plane. If the angle of dip at that place is 60$°$ and the magnet is restricted to oscillate in the horizontal plane, then the time period of oscillations will be :

1. T

2. $\frac{T}{\sqrt{2}}$

3. $\sqrt{2}T$

4. 2T

The magnetic susceptibility of a substance is -0.0002 at room temperature. If this substance is kept in a uniform external magnetic field B, the net field inside the substance becomes B', then :

1. B'$>$B

2. B'$<$B

3. B' = B

4. B' = 0

The true value of the angle of dip at a place is $\theta$. If the plane of the dip circle is at 30$°$ with the magnetic meridian, the angle of dip is $\theta$'. Then one concludes that :

1. $\theta$' = $\theta$

2. $\theta$'$<$$\theta$

3. $\theta$'$>$$\theta$

4. $\theta$' = $\theta$+30$°$

A diamagnetic substance is kept in a uniform external magnetic field B. If the net magnetic field inside the substance is B', then

1. B'$<$B

2. B' = B

3. B'$>$B

4. Any of the above