The magnitude of the magnetic field at the center of an equilateral triangular loop of side $1 \ m$ which is carrying a current of $10 \ A$ is $.... \mu T$.

$A$ current carrying circular coil of radius $R$ produces magnetic fields $B_1$ and $B_2$ at an axial point $P$ at a distance $x$ from its centre and at a point $Q$ placed at its centre respectively. If $B_1 = \frac{B_2}{8}$,the value of $x$ is

Write the formula for the magnetic field due to a circular current-carrying loop having $N$ turns and $R$ radius at a point on the axis of the loop at a distance $x$ from the center.

$A$ coil of $n$ number of turns is wound tightly in the form of a spiral with inner and outer radii $a$ and $b$ respectively. When a current of strength $I$ is passed through the coil,the magnetic field at its centre is

The magnitude of magnetic induction at the mid-point $O$ due to the current arrangement as shown in the figure will be:

If a battery of $12 \text{ V}$ is connected across the diametrically opposite points $A$ and $B$ of a conducting ring of radius $R$ and the current drawn from the battery is $I$,then the magnetic field produced at the centre of the ring due to the ring is . . . . . . .