00. Biot-Savart's Law and Magnetic Field, Lorentz Force
Moving Charges & Magnetism

153244 Cathode rays enter a magnetic field making oblique angle with the lines of magnetic induction. What will be nature of the path followed?

1 Parabola
2 Helix
3 Circle
4 Straight line
Moving Charges & Magnetism

153248 A cylindrical conducting rod is kept with its axis along positive $z$-axis, where a uniform magnetic field exists parallel to z-axis. The current induced in the cylinder is

1 zero
2 clockwise as seen from $+z$-axis
3 anti-clockwise as seen from $+z$-axis
4 opposite to the direction of magnetic field
Moving Charges & Magnetism

153250 A direct current $I$ flows along the length of an infinitely long straight thin walled pipe, then the magnetic field is

1 uniform throughout the pipe but not zero
2 zero only along the axis of the pipe
3 zero at any point inside the pipe
4 maximum at the centre and minimum at the edge
Moving Charges & Magnetism

153257 A conducting square loop of side $l$ and resistance $R$ move in its own plane with uniform velocity $v$ perpendicular to one of its sides. A magnetic field $B$, constant in time and space, pointing perpendicular and into the plane of the loop exists everywhere. The current induced in the loop is

1 $\mathrm{B} / \mathrm{v} / \mathrm{R}$ clockwise
2 $\mathrm{B} / \mathrm{v} / \mathrm{R}$ anti-clockwise
3 $2 \mathrm{~B} l \mathrm{v} / \mathrm{R}$ anti-clockwise
4 zero
Moving Charges & Magnetism

153288 The current density varies with radial distance $\mathbf{r}$ as $J=\mathbf{a r}^{2}$, in a cylindrical wire of radius $R$. The current passing through the wire between radial distance $R / 3$ and $R / 2$ is

1 $\frac{65 \pi \mathrm{aR}^{4}}{2592}$
2 $\frac{25 \pi \mathrm{aR}^{4}}{72}$
3 $\frac{65 \pi \mathrm{a}^{2} \mathrm{R}^{3}}{2938}$
4 $\frac{81 \pi \mathrm{a}^{2} \mathrm{R}^{4}}{144}$
Moving Charges & Magnetism

153244 Cathode rays enter a magnetic field making oblique angle with the lines of magnetic induction. What will be nature of the path followed?

1 Parabola
2 Helix
3 Circle
4 Straight line
Moving Charges & Magnetism

153248 A cylindrical conducting rod is kept with its axis along positive $z$-axis, where a uniform magnetic field exists parallel to z-axis. The current induced in the cylinder is

1 zero
2 clockwise as seen from $+z$-axis
3 anti-clockwise as seen from $+z$-axis
4 opposite to the direction of magnetic field
Moving Charges & Magnetism

153250 A direct current $I$ flows along the length of an infinitely long straight thin walled pipe, then the magnetic field is

1 uniform throughout the pipe but not zero
2 zero only along the axis of the pipe
3 zero at any point inside the pipe
4 maximum at the centre and minimum at the edge
Moving Charges & Magnetism

153257 A conducting square loop of side $l$ and resistance $R$ move in its own plane with uniform velocity $v$ perpendicular to one of its sides. A magnetic field $B$, constant in time and space, pointing perpendicular and into the plane of the loop exists everywhere. The current induced in the loop is

1 $\mathrm{B} / \mathrm{v} / \mathrm{R}$ clockwise
2 $\mathrm{B} / \mathrm{v} / \mathrm{R}$ anti-clockwise
3 $2 \mathrm{~B} l \mathrm{v} / \mathrm{R}$ anti-clockwise
4 zero
Moving Charges & Magnetism

153288 The current density varies with radial distance $\mathbf{r}$ as $J=\mathbf{a r}^{2}$, in a cylindrical wire of radius $R$. The current passing through the wire between radial distance $R / 3$ and $R / 2$ is

1 $\frac{65 \pi \mathrm{aR}^{4}}{2592}$
2 $\frac{25 \pi \mathrm{aR}^{4}}{72}$
3 $\frac{65 \pi \mathrm{a}^{2} \mathrm{R}^{3}}{2938}$
4 $\frac{81 \pi \mathrm{a}^{2} \mathrm{R}^{4}}{144}$
Moving Charges & Magnetism

153244 Cathode rays enter a magnetic field making oblique angle with the lines of magnetic induction. What will be nature of the path followed?

1 Parabola
2 Helix
3 Circle
4 Straight line
Moving Charges & Magnetism

153248 A cylindrical conducting rod is kept with its axis along positive $z$-axis, where a uniform magnetic field exists parallel to z-axis. The current induced in the cylinder is

1 zero
2 clockwise as seen from $+z$-axis
3 anti-clockwise as seen from $+z$-axis
4 opposite to the direction of magnetic field
Moving Charges & Magnetism

153250 A direct current $I$ flows along the length of an infinitely long straight thin walled pipe, then the magnetic field is

1 uniform throughout the pipe but not zero
2 zero only along the axis of the pipe
3 zero at any point inside the pipe
4 maximum at the centre and minimum at the edge
Moving Charges & Magnetism

153257 A conducting square loop of side $l$ and resistance $R$ move in its own plane with uniform velocity $v$ perpendicular to one of its sides. A magnetic field $B$, constant in time and space, pointing perpendicular and into the plane of the loop exists everywhere. The current induced in the loop is

1 $\mathrm{B} / \mathrm{v} / \mathrm{R}$ clockwise
2 $\mathrm{B} / \mathrm{v} / \mathrm{R}$ anti-clockwise
3 $2 \mathrm{~B} l \mathrm{v} / \mathrm{R}$ anti-clockwise
4 zero
Moving Charges & Magnetism

153288 The current density varies with radial distance $\mathbf{r}$ as $J=\mathbf{a r}^{2}$, in a cylindrical wire of radius $R$. The current passing through the wire between radial distance $R / 3$ and $R / 2$ is

1 $\frac{65 \pi \mathrm{aR}^{4}}{2592}$
2 $\frac{25 \pi \mathrm{aR}^{4}}{72}$
3 $\frac{65 \pi \mathrm{a}^{2} \mathrm{R}^{3}}{2938}$
4 $\frac{81 \pi \mathrm{a}^{2} \mathrm{R}^{4}}{144}$
Moving Charges & Magnetism

153244 Cathode rays enter a magnetic field making oblique angle with the lines of magnetic induction. What will be nature of the path followed?

1 Parabola
2 Helix
3 Circle
4 Straight line
Moving Charges & Magnetism

153248 A cylindrical conducting rod is kept with its axis along positive $z$-axis, where a uniform magnetic field exists parallel to z-axis. The current induced in the cylinder is

1 zero
2 clockwise as seen from $+z$-axis
3 anti-clockwise as seen from $+z$-axis
4 opposite to the direction of magnetic field
Moving Charges & Magnetism

153250 A direct current $I$ flows along the length of an infinitely long straight thin walled pipe, then the magnetic field is

1 uniform throughout the pipe but not zero
2 zero only along the axis of the pipe
3 zero at any point inside the pipe
4 maximum at the centre and minimum at the edge
Moving Charges & Magnetism

153257 A conducting square loop of side $l$ and resistance $R$ move in its own plane with uniform velocity $v$ perpendicular to one of its sides. A magnetic field $B$, constant in time and space, pointing perpendicular and into the plane of the loop exists everywhere. The current induced in the loop is

1 $\mathrm{B} / \mathrm{v} / \mathrm{R}$ clockwise
2 $\mathrm{B} / \mathrm{v} / \mathrm{R}$ anti-clockwise
3 $2 \mathrm{~B} l \mathrm{v} / \mathrm{R}$ anti-clockwise
4 zero
Moving Charges & Magnetism

153288 The current density varies with radial distance $\mathbf{r}$ as $J=\mathbf{a r}^{2}$, in a cylindrical wire of radius $R$. The current passing through the wire between radial distance $R / 3$ and $R / 2$ is

1 $\frac{65 \pi \mathrm{aR}^{4}}{2592}$
2 $\frac{25 \pi \mathrm{aR}^{4}}{72}$
3 $\frac{65 \pi \mathrm{a}^{2} \mathrm{R}^{3}}{2938}$
4 $\frac{81 \pi \mathrm{a}^{2} \mathrm{R}^{4}}{144}$
Moving Charges & Magnetism

153244 Cathode rays enter a magnetic field making oblique angle with the lines of magnetic induction. What will be nature of the path followed?

1 Parabola
2 Helix
3 Circle
4 Straight line
Moving Charges & Magnetism

153248 A cylindrical conducting rod is kept with its axis along positive $z$-axis, where a uniform magnetic field exists parallel to z-axis. The current induced in the cylinder is

1 zero
2 clockwise as seen from $+z$-axis
3 anti-clockwise as seen from $+z$-axis
4 opposite to the direction of magnetic field
Moving Charges & Magnetism

153250 A direct current $I$ flows along the length of an infinitely long straight thin walled pipe, then the magnetic field is

1 uniform throughout the pipe but not zero
2 zero only along the axis of the pipe
3 zero at any point inside the pipe
4 maximum at the centre and minimum at the edge
Moving Charges & Magnetism

153257 A conducting square loop of side $l$ and resistance $R$ move in its own plane with uniform velocity $v$ perpendicular to one of its sides. A magnetic field $B$, constant in time and space, pointing perpendicular and into the plane of the loop exists everywhere. The current induced in the loop is

1 $\mathrm{B} / \mathrm{v} / \mathrm{R}$ clockwise
2 $\mathrm{B} / \mathrm{v} / \mathrm{R}$ anti-clockwise
3 $2 \mathrm{~B} l \mathrm{v} / \mathrm{R}$ anti-clockwise
4 zero
Moving Charges & Magnetism

153288 The current density varies with radial distance $\mathbf{r}$ as $J=\mathbf{a r}^{2}$, in a cylindrical wire of radius $R$. The current passing through the wire between radial distance $R / 3$ and $R / 2$ is

1 $\frac{65 \pi \mathrm{aR}^{4}}{2592}$
2 $\frac{25 \pi \mathrm{aR}^{4}}{72}$
3 $\frac{65 \pi \mathrm{a}^{2} \mathrm{R}^{3}}{2938}$
4 $\frac{81 \pi \mathrm{a}^{2} \mathrm{R}^{4}}{144}$