Embibe Experts Solutions for Chapter: Magnetic Effect of Current, Exercise 3: Exercise (Previous Year Questions)

A current $i$ is flowing through wire $PQR$. This wire is bent in the form of an angle and placed in uniform magnetic field $B$ according to figure. If $PQ=l$ and $\angle$$PQR=60°$, the ratio of magnetic forces on $PQ$ to $QR$, respectively, is,

Three long straight wires carrying currents are arranged according to figure. Magnetic force on $10 \mathrm{cm}$ part of the wire $Q$ is,

A rectangular loop $ABCD$ is placed near an infinite length current carrying wire. Magnetic force on the loop is,

A long horizontal wire is rigidly fixed and carries $100 \mathrm{A}$ current. Another wire of linear mass density $2\times {10}^{-3} \mathrm{kg} {\mathrm{m}}^{-1}$ is placed below and parallel to the fixed wire. If the free wire kept $2 \mathrm{cm}$ below hangs in air, then current in free wire is,

A square current carrying loop of side ’a’ produced magnetic field at its centre is ’B’. Find magnetic moment of this loop in terms of ’B’.

A wire of length '$\mathcal{l}$’ carries a current bent into various regular polygons shown below. Find magnetic moment in terms of length of the wire. Circular loop.

Four wires each of length $2.0 \mathrm{m}$, are bent in four-loop $P,Q,R$ and $S$ then suspended in uniform magnetic field. All loop carries equal currents, which statement of the following is true :

A solenoid of radius $R$ and length $L$ has a current $I=I_0 \cos \omega t.$ The value of induced electric field at a distance of $r$ outside the solenoid, is