Match the items in List-$I$ with the items in List-$II$:
| List-$I$ | List-$II$ |
| :--- | :--- |
| $(A)$ High retentivity | $(i)$ Telephone diaphragm |
| $(B)$ High resistivity | (ii) Diamagnet |
| $(C)$ Low coercivity | (iii) To decrease eddy current losses |
| $(D)$ Negative susceptibility | (iv) Permanent magnet |

$A$ bar magnet is placed with its north pole pointing towards the geographic north. The magnetic field at a point $P$ on its equatorial line is zero. If the magnet is rotated by $90^\circ$,what will be the magnetic field at point $P$? The horizontal component of the Earth's magnetic field is $B_H$.

Answer the following questions:
$(a)$ Why does a paramagnetic sample display greater magnetisation (for the same magnetising field) when cooled?
$(b)$ Why is diamagnetism, in contrast, almost independent of temperature?
$(c)$ If a toroid uses bismuth for its core, will the field in the core be (slightly) greater or (slightly) less than when the core is empty?
$(d)$ Is the permeability of a ferromagnetic material independent of the magnetic field? If not, is it more for lower or higher fields?
$(e)$ Magnetic field lines are always nearly normal to the surface of a ferromagnet at every point. (This fact is analogous to the static electric field lines being normal to the surface of a conductor at every point.) Why?
$(f)$ Would the maximum possible magnetisation of a paramagnetic sample be of the same order of magnitude as the magnetisation of a ferromagnet?

Some physical quantities are given in List-$I$ and their related units are given in List-$II$. Match the correct pairs.

List-$I$	List-$II$
$(A)$ Magnetic field intensity	$(i)$ $Wb$
$(B)$ Magnetic flux	(ii) $Wb \cdot m^{-2}$
$(C)$ Magnetic pole strength	(iii) $A \cdot m$
$(D)$ Magnetic induction	(iv) $A \cdot m^{-1}$

$A$ bar magnet has a total length $2l = 20$ units and the field point $P$ is at a distance $d = 10$ units from the centre of the magnet. If the relative uncertainty of length measurement is $1\%$,then the uncertainty of the magnetic field at point $P$ is

Assertion: Magnetic Resonance Imaging $(MRI)$ is a useful diagnostic tool for producing images of various parts of the human body.
Reason: Protons of various tissues of the human body play a role in $(MRI)$.