Magnetostatic screening or shielding can be created by

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 |

Demagnetisation of magnets can be done by

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) $A \cdot m^{-1}$

Two identical bar magnets with a length of $10 \, cm$ and a weight of $50 \, g$ are placed freely with their like poles facing each other in an inverted vertical glass tube. The upper magnet hangs in the air above the lower one such that the distance between the nearest poles of the magnets is $3 \, mm$. The pole strength of each magnet is approximately ....... $A \cdot m$.

Many of the diagrams given in the figure show magnetic field lines (thick lines in the figure) wrongly. Point out what is wrong with them. Some of them may describe electrostatic field lines correctly. Point out which ones.