Find out magnetic field at point $O$ ?
$\pi\times {10^{ - 5}}\,T$
$\pi\times {10^{ - 4}}\,T$
$\pi\times {10^{ - 1}}\,T$
${10^{ - 5}}\,T$
A thin rod is bent in the shape of a small circle of radius $'r'$. If the charge per unit length of the rod is $'\sigma ',$ and if the circle is rotated about its axis at the rate of $'n'$ rotation per second, the magnetic induction at a point on the axis at a large distance $'y'$ from the centre is
Gauss is unit of which quantity
A battery is connected between two points $A$ and $B$ on the circumference of a uniform conducting ring of radius $r$ and resistance $R$. One of the arcs $AB$ of the ring subtends an angle $\theta $ at the centre. The value of the magnetic induction at the centre due to the current in the ring is
Current $i$ is passed as shown in diagram. If radius of the circle is a, then the magnetic flux density at the centre $P$ will be:
The following statement is false for Helmholtz coils