04. Force and Torque on Current Carrying Conductor
Moving Charges & Magnetism

153813 A wire of length $l$ carrying a current $I A$ is bent into a circle. The magnitude of the magnetic moment is-

1 $\frac{l \mathrm{I}^{2}}{2 \pi}$
2 $\frac{l \mathrm{I}^{2}}{4 \pi}$
3 $\frac{l^{2} \mathrm{I}}{2 \pi}$
4 $\frac{l^{2} \mathrm{I}}{4 \pi}$
Moving Charges & Magnetism

153814 A horizontal rod of mass $0.01 \mathrm{~kg}$ and length 10 $\mathrm{cm}$ is placed on a frictionless plane inclined at an angle $60^{\circ}$ with the horizontal and with the length of rod parallel to the edge of the inclined plane. A uniform magnetic field is applied 'Vertically downwards. If the current through the rod is $1.73 \mathrm{~A}$, Then the value of magnetic field induction $B$ for which the rod remains stationary on the inclined plane is

1 $1 \mathrm{~T}$
2 $3 \mathrm{~T}$
3 $2.5 \mathrm{~T}$
4 $4 \mathrm{~T}$
Moving Charges & Magnetism

153816 A conducting wire carrying current is arranged as shown in the figure. The magnetic field at $O$ is:

1 $\frac{\mu_{0} \mathrm{i}}{12}\left[\frac{1}{\mathrm{R}_{1}}-\frac{1}{\mathrm{R}_{2}}\right]$
2 $\frac{\mu_{0} \mathrm{i}}{12}\left[\frac{1}{\mathrm{R}_{1}}+\frac{1}{\mathrm{R}_{2}}\right]$
3 $\frac{\mu_{0} \mathrm{i}}{6}\left[\frac{1}{\mathrm{R}_{1}}-\frac{1}{\mathrm{R}_{2}}\right]$
4 $\frac{\mu_{0} \mathrm{i}}{6}\left[\frac{1}{\mathrm{R}_{1}}+\frac{1}{\mathrm{R}_{2}}\right]$
Moving Charges & Magnetism

153817 Three long, straight parallel wires, carrying current, are arranged as shown in figure. The force experienced by a $25 \mathrm{~cm}$ length of wire $C$ is:

1 $10^{-3} \mathrm{~N}$
2 $2.5 \times 10^{-3} \mathrm{~N}$
3 zero
4 $1.5 \times 10^{-3} \mathrm{~N}$
Moving Charges & Magnetism

153819 A circular coil of 20 turns and radius $10 \mathrm{~cm}$ is placed in uniform magnetic field of $0.10 \mathrm{~T}$ normal to the plane of the coil. If the current in coil is $5 \mathrm{~A}$, then the torque acting on the coil will be

1 $31.4 \mathrm{~N} \mathrm{~m}$
2 $3.14 \mathrm{~N} \mathrm{~m}$
3 $0.314 \mathrm{~N} \mathrm{~m}$
4 zero
Moving Charges & Magnetism

153813 A wire of length $l$ carrying a current $I A$ is bent into a circle. The magnitude of the magnetic moment is-

1 $\frac{l \mathrm{I}^{2}}{2 \pi}$
2 $\frac{l \mathrm{I}^{2}}{4 \pi}$
3 $\frac{l^{2} \mathrm{I}}{2 \pi}$
4 $\frac{l^{2} \mathrm{I}}{4 \pi}$
Moving Charges & Magnetism

153814 A horizontal rod of mass $0.01 \mathrm{~kg}$ and length 10 $\mathrm{cm}$ is placed on a frictionless plane inclined at an angle $60^{\circ}$ with the horizontal and with the length of rod parallel to the edge of the inclined plane. A uniform magnetic field is applied 'Vertically downwards. If the current through the rod is $1.73 \mathrm{~A}$, Then the value of magnetic field induction $B$ for which the rod remains stationary on the inclined plane is

1 $1 \mathrm{~T}$
2 $3 \mathrm{~T}$
3 $2.5 \mathrm{~T}$
4 $4 \mathrm{~T}$
Moving Charges & Magnetism

153816 A conducting wire carrying current is arranged as shown in the figure. The magnetic field at $O$ is:

1 $\frac{\mu_{0} \mathrm{i}}{12}\left[\frac{1}{\mathrm{R}_{1}}-\frac{1}{\mathrm{R}_{2}}\right]$
2 $\frac{\mu_{0} \mathrm{i}}{12}\left[\frac{1}{\mathrm{R}_{1}}+\frac{1}{\mathrm{R}_{2}}\right]$
3 $\frac{\mu_{0} \mathrm{i}}{6}\left[\frac{1}{\mathrm{R}_{1}}-\frac{1}{\mathrm{R}_{2}}\right]$
4 $\frac{\mu_{0} \mathrm{i}}{6}\left[\frac{1}{\mathrm{R}_{1}}+\frac{1}{\mathrm{R}_{2}}\right]$
Moving Charges & Magnetism

153817 Three long, straight parallel wires, carrying current, are arranged as shown in figure. The force experienced by a $25 \mathrm{~cm}$ length of wire $C$ is:

1 $10^{-3} \mathrm{~N}$
2 $2.5 \times 10^{-3} \mathrm{~N}$
3 zero
4 $1.5 \times 10^{-3} \mathrm{~N}$
Moving Charges & Magnetism

153819 A circular coil of 20 turns and radius $10 \mathrm{~cm}$ is placed in uniform magnetic field of $0.10 \mathrm{~T}$ normal to the plane of the coil. If the current in coil is $5 \mathrm{~A}$, then the torque acting on the coil will be

1 $31.4 \mathrm{~N} \mathrm{~m}$
2 $3.14 \mathrm{~N} \mathrm{~m}$
3 $0.314 \mathrm{~N} \mathrm{~m}$
4 zero
Moving Charges & Magnetism

153813 A wire of length $l$ carrying a current $I A$ is bent into a circle. The magnitude of the magnetic moment is-

1 $\frac{l \mathrm{I}^{2}}{2 \pi}$
2 $\frac{l \mathrm{I}^{2}}{4 \pi}$
3 $\frac{l^{2} \mathrm{I}}{2 \pi}$
4 $\frac{l^{2} \mathrm{I}}{4 \pi}$
Moving Charges & Magnetism

153814 A horizontal rod of mass $0.01 \mathrm{~kg}$ and length 10 $\mathrm{cm}$ is placed on a frictionless plane inclined at an angle $60^{\circ}$ with the horizontal and with the length of rod parallel to the edge of the inclined plane. A uniform magnetic field is applied 'Vertically downwards. If the current through the rod is $1.73 \mathrm{~A}$, Then the value of magnetic field induction $B$ for which the rod remains stationary on the inclined plane is

1 $1 \mathrm{~T}$
2 $3 \mathrm{~T}$
3 $2.5 \mathrm{~T}$
4 $4 \mathrm{~T}$
Moving Charges & Magnetism

153816 A conducting wire carrying current is arranged as shown in the figure. The magnetic field at $O$ is:

1 $\frac{\mu_{0} \mathrm{i}}{12}\left[\frac{1}{\mathrm{R}_{1}}-\frac{1}{\mathrm{R}_{2}}\right]$
2 $\frac{\mu_{0} \mathrm{i}}{12}\left[\frac{1}{\mathrm{R}_{1}}+\frac{1}{\mathrm{R}_{2}}\right]$
3 $\frac{\mu_{0} \mathrm{i}}{6}\left[\frac{1}{\mathrm{R}_{1}}-\frac{1}{\mathrm{R}_{2}}\right]$
4 $\frac{\mu_{0} \mathrm{i}}{6}\left[\frac{1}{\mathrm{R}_{1}}+\frac{1}{\mathrm{R}_{2}}\right]$
Moving Charges & Magnetism

153817 Three long, straight parallel wires, carrying current, are arranged as shown in figure. The force experienced by a $25 \mathrm{~cm}$ length of wire $C$ is:

1 $10^{-3} \mathrm{~N}$
2 $2.5 \times 10^{-3} \mathrm{~N}$
3 zero
4 $1.5 \times 10^{-3} \mathrm{~N}$
Moving Charges & Magnetism

153819 A circular coil of 20 turns and radius $10 \mathrm{~cm}$ is placed in uniform magnetic field of $0.10 \mathrm{~T}$ normal to the plane of the coil. If the current in coil is $5 \mathrm{~A}$, then the torque acting on the coil will be

1 $31.4 \mathrm{~N} \mathrm{~m}$
2 $3.14 \mathrm{~N} \mathrm{~m}$
3 $0.314 \mathrm{~N} \mathrm{~m}$
4 zero
Moving Charges & Magnetism

153813 A wire of length $l$ carrying a current $I A$ is bent into a circle. The magnitude of the magnetic moment is-

1 $\frac{l \mathrm{I}^{2}}{2 \pi}$
2 $\frac{l \mathrm{I}^{2}}{4 \pi}$
3 $\frac{l^{2} \mathrm{I}}{2 \pi}$
4 $\frac{l^{2} \mathrm{I}}{4 \pi}$
Moving Charges & Magnetism

153814 A horizontal rod of mass $0.01 \mathrm{~kg}$ and length 10 $\mathrm{cm}$ is placed on a frictionless plane inclined at an angle $60^{\circ}$ with the horizontal and with the length of rod parallel to the edge of the inclined plane. A uniform magnetic field is applied 'Vertically downwards. If the current through the rod is $1.73 \mathrm{~A}$, Then the value of magnetic field induction $B$ for which the rod remains stationary on the inclined plane is

1 $1 \mathrm{~T}$
2 $3 \mathrm{~T}$
3 $2.5 \mathrm{~T}$
4 $4 \mathrm{~T}$
Moving Charges & Magnetism

153816 A conducting wire carrying current is arranged as shown in the figure. The magnetic field at $O$ is:

1 $\frac{\mu_{0} \mathrm{i}}{12}\left[\frac{1}{\mathrm{R}_{1}}-\frac{1}{\mathrm{R}_{2}}\right]$
2 $\frac{\mu_{0} \mathrm{i}}{12}\left[\frac{1}{\mathrm{R}_{1}}+\frac{1}{\mathrm{R}_{2}}\right]$
3 $\frac{\mu_{0} \mathrm{i}}{6}\left[\frac{1}{\mathrm{R}_{1}}-\frac{1}{\mathrm{R}_{2}}\right]$
4 $\frac{\mu_{0} \mathrm{i}}{6}\left[\frac{1}{\mathrm{R}_{1}}+\frac{1}{\mathrm{R}_{2}}\right]$
Moving Charges & Magnetism

153817 Three long, straight parallel wires, carrying current, are arranged as shown in figure. The force experienced by a $25 \mathrm{~cm}$ length of wire $C$ is:

1 $10^{-3} \mathrm{~N}$
2 $2.5 \times 10^{-3} \mathrm{~N}$
3 zero
4 $1.5 \times 10^{-3} \mathrm{~N}$
Moving Charges & Magnetism

153819 A circular coil of 20 turns and radius $10 \mathrm{~cm}$ is placed in uniform magnetic field of $0.10 \mathrm{~T}$ normal to the plane of the coil. If the current in coil is $5 \mathrm{~A}$, then the torque acting on the coil will be

1 $31.4 \mathrm{~N} \mathrm{~m}$
2 $3.14 \mathrm{~N} \mathrm{~m}$
3 $0.314 \mathrm{~N} \mathrm{~m}$
4 zero
Moving Charges & Magnetism

153813 A wire of length $l$ carrying a current $I A$ is bent into a circle. The magnitude of the magnetic moment is-

1 $\frac{l \mathrm{I}^{2}}{2 \pi}$
2 $\frac{l \mathrm{I}^{2}}{4 \pi}$
3 $\frac{l^{2} \mathrm{I}}{2 \pi}$
4 $\frac{l^{2} \mathrm{I}}{4 \pi}$
Moving Charges & Magnetism

153814 A horizontal rod of mass $0.01 \mathrm{~kg}$ and length 10 $\mathrm{cm}$ is placed on a frictionless plane inclined at an angle $60^{\circ}$ with the horizontal and with the length of rod parallel to the edge of the inclined plane. A uniform magnetic field is applied 'Vertically downwards. If the current through the rod is $1.73 \mathrm{~A}$, Then the value of magnetic field induction $B$ for which the rod remains stationary on the inclined plane is

1 $1 \mathrm{~T}$
2 $3 \mathrm{~T}$
3 $2.5 \mathrm{~T}$
4 $4 \mathrm{~T}$
Moving Charges & Magnetism

153816 A conducting wire carrying current is arranged as shown in the figure. The magnetic field at $O$ is:

1 $\frac{\mu_{0} \mathrm{i}}{12}\left[\frac{1}{\mathrm{R}_{1}}-\frac{1}{\mathrm{R}_{2}}\right]$
2 $\frac{\mu_{0} \mathrm{i}}{12}\left[\frac{1}{\mathrm{R}_{1}}+\frac{1}{\mathrm{R}_{2}}\right]$
3 $\frac{\mu_{0} \mathrm{i}}{6}\left[\frac{1}{\mathrm{R}_{1}}-\frac{1}{\mathrm{R}_{2}}\right]$
4 $\frac{\mu_{0} \mathrm{i}}{6}\left[\frac{1}{\mathrm{R}_{1}}+\frac{1}{\mathrm{R}_{2}}\right]$
Moving Charges & Magnetism

153817 Three long, straight parallel wires, carrying current, are arranged as shown in figure. The force experienced by a $25 \mathrm{~cm}$ length of wire $C$ is:

1 $10^{-3} \mathrm{~N}$
2 $2.5 \times 10^{-3} \mathrm{~N}$
3 zero
4 $1.5 \times 10^{-3} \mathrm{~N}$
Moving Charges & Magnetism

153819 A circular coil of 20 turns and radius $10 \mathrm{~cm}$ is placed in uniform magnetic field of $0.10 \mathrm{~T}$ normal to the plane of the coil. If the current in coil is $5 \mathrm{~A}$, then the torque acting on the coil will be

1 $31.4 \mathrm{~N} \mathrm{~m}$
2 $3.14 \mathrm{~N} \mathrm{~m}$
3 $0.314 \mathrm{~N} \mathrm{~m}$
4 zero