Two magnets, each of magnetic moment $‘M’ $ are placed so as to form a cross at right angles to each other. The magnetic moment of the system will be

Two like magnetic poles of strength $ 10$  and $40$ $ SI$ units are separated by a distance $30 \,cm$. The intensity of magnetic field is zero on the line joining them

Magnetic field intensity is defined as

A short bar magnet of magnetic movement $5.25 \times 10^{-2} \;J\, T ^{-1}$ is placed with its axis perpendicular to the earth's field direction. At what distance from the centre of the magnet, the resultant field is inclined at $45^{\circ}$ with earth's field on

$(a)$ its normal bisector and

$(b)$ its axis.

Magnitude of the earth's field at the place is given to be $0.42 \;G$. Ignore the length of the magnet in comparison to the distances involved.

A straight magnetic strip has a magnetic moment of $44 \mathrm{Am}^2$. If the strip is bent in a semicircular shape, its magnetic moment will be .. . . . . . .$\mathrm{Am}^2$ $\left(\right.$ Given $\left.\pi=\frac{22}{7}\right)$