JEE Main · 2004 · 24 Apr 2004 · Offline · Magnetic Effects of Current

An infinitely long straight wire carrying current I is bent in a planer shape as shown in the diagram. The radius of the circular part is r . The magnetic field at the centre O of the circular loop is :

The current passing through a conducting loop in the form of equilateral triangle of side $4\sqrt{3}\mathrm{cm}$ is 2A. The magnetic field at its centroid is $\alpha \times 10^{-5}\mathrm{T}$. The value of $\alpha$ is ____.
(Given : …

Three long straight wires carrying current are arranged mutually parallel as shown in the figure. The force experienced by 15 cm length of wire $Q$ is ______.
(${\mu }_0=4\pi \times 10^{-7}\mathrm{T}.\mathrm{m}/\mathrm{A}$)

The magnetic field at the centre of a current carrying circular loop of radius $R$ is $16\mu \mathrm{T}$. The magnetic field at a distance $x=\sqrt{3}R$ on its axis from the centre is ____ $\mu \mathrm{T}$.

Two identical circular loops P and Q each of radius r are lying in parallel planes such that they have common axis. The current through P and Q are I and 4I respectively in clockwise direction as seen from O. The net magnetic field at O is:

A long cylindrical conductor with large cross section carries an electric current distributed uniformly over its cross-section. Magnetic field due to this current is :
A. maximum at either ends of the conductor and minimum at the midpoint
B. maximum at the axis of the conductor
C …