The magnetic field at the centre of a circular current carrying-conductor of radius $r$ is $B_c$. The magnetic field on its axis at a distance $r$ from the centre is $B_a$. The value of $B_c$ : $B_a$ will be
$1:\sqrt 2 $
$1:2\sqrt 2 $
$2\sqrt 2 :1$
$\sqrt 2 :1$
the magnetic induction at $O$ due to the whole length of the conductor is
What is the magnetic field at a distance $R$ from a coil of radius $r$ carrying current $I$ ?
A coil carrying a heavy current and having large number of turns mounted in a $N-S$ vertical plane and $a$ current flows in clockwise direction. A small magnetic needle at its cente will have its north pole in
A steady current is set up in a cubic network composed of wires of equal resistance and length $d$ as shown in figure. What is the magnetic field at the centre P due to the cubic network
A very long conducting wire is bent in a semicircular shape from $A$ to $B$ as shown in figure. The magnetic field at point $P$ for steady current configuration is given by: