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

153182 A square conducting loop is placed near an infinitely long current carrying wire with one edge parallel to the wire as shown in the figure. If the current in the straight wire is suddenly halved, which of the following statements will be true?
"The loop will .....".

1 stay stationary
2 move towards the wire
3 move away from the wire
4 move parallel to the wire
Moving Charges & Magnetism

153183 An electric current ' $I$ ' enters and leaves a uniform circular wire of radius $r$ through diametrically opposite points. A particle carrying a charge $q$ moves along the axis of the circular wire with speed $v$. What is the magnetic force experienced by the particle when it passes through the centre of the circle?

1 $\mathrm{qv} \frac{\mu_{0} \mathrm{i}}{\mathrm{a}}$
2 $\mathrm{qv} \frac{\mu_{0} \mathrm{i}}{2 \mathrm{a}}$
3 $\mathrm{qv} \frac{\mu_{0} \mathrm{i}}{2 \pi \mathrm{a}}$
4 Zero
Moving Charges & Magnetism

153184 A very long wire carrying a current $4 \sqrt{2} \mathrm{~A}$ is bent at a right angles. The magnitude of magnetic field $(|\mathrm{B}|)$ at a point $P$ lying on a line perpendicular to the bent wire at a distance, $d$ $=20 \mathrm{~cm}$ from the point of the bending will be (Let $\mu_{0}=4 \pi \times 10^{-7} \mathrm{H} / \mathrm{m}$ )

1 $1 \mu \mathrm{T}$
2 $0.8 \mu \mathrm{T}$
3 $2 \mu \mathrm{T}$
4 $4 \mu \mathrm{T}$
Moving Charges & Magnetism

153185 The magnetic field normal to the plane of a coil of $\mathbf{N}$ turns and radius $\mathbf{r}$ which carries a current $i$ is measured on the axis of the coil at a distance $h$ from the centre of the coil. This is smaller than the field at the centre by the fraction,

1 $\frac{3}{2} \cdot \frac{\mathrm{h}^{2}}{\mathrm{r}^{2}}$
2 $\frac{2}{3} \cdot \frac{\mathrm{h}^{2}}{\mathrm{r}^{2}}$
3 $\frac{3}{2} \cdot \frac{\mathrm{r}^{2}}{\mathrm{~h}^{2}}$
4 $\frac{2}{3} \cdot \frac{\mathrm{r}^{2}}{\mathrm{~h}^{2}}$
Moving Charges & Magnetism

153182 A square conducting loop is placed near an infinitely long current carrying wire with one edge parallel to the wire as shown in the figure. If the current in the straight wire is suddenly halved, which of the following statements will be true?
"The loop will .....".

1 stay stationary
2 move towards the wire
3 move away from the wire
4 move parallel to the wire
Moving Charges & Magnetism

153183 An electric current ' $I$ ' enters and leaves a uniform circular wire of radius $r$ through diametrically opposite points. A particle carrying a charge $q$ moves along the axis of the circular wire with speed $v$. What is the magnetic force experienced by the particle when it passes through the centre of the circle?

1 $\mathrm{qv} \frac{\mu_{0} \mathrm{i}}{\mathrm{a}}$
2 $\mathrm{qv} \frac{\mu_{0} \mathrm{i}}{2 \mathrm{a}}$
3 $\mathrm{qv} \frac{\mu_{0} \mathrm{i}}{2 \pi \mathrm{a}}$
4 Zero
Moving Charges & Magnetism

153184 A very long wire carrying a current $4 \sqrt{2} \mathrm{~A}$ is bent at a right angles. The magnitude of magnetic field $(|\mathrm{B}|)$ at a point $P$ lying on a line perpendicular to the bent wire at a distance, $d$ $=20 \mathrm{~cm}$ from the point of the bending will be (Let $\mu_{0}=4 \pi \times 10^{-7} \mathrm{H} / \mathrm{m}$ )

1 $1 \mu \mathrm{T}$
2 $0.8 \mu \mathrm{T}$
3 $2 \mu \mathrm{T}$
4 $4 \mu \mathrm{T}$
Moving Charges & Magnetism

153185 The magnetic field normal to the plane of a coil of $\mathbf{N}$ turns and radius $\mathbf{r}$ which carries a current $i$ is measured on the axis of the coil at a distance $h$ from the centre of the coil. This is smaller than the field at the centre by the fraction,

1 $\frac{3}{2} \cdot \frac{\mathrm{h}^{2}}{\mathrm{r}^{2}}$
2 $\frac{2}{3} \cdot \frac{\mathrm{h}^{2}}{\mathrm{r}^{2}}$
3 $\frac{3}{2} \cdot \frac{\mathrm{r}^{2}}{\mathrm{~h}^{2}}$
4 $\frac{2}{3} \cdot \frac{\mathrm{r}^{2}}{\mathrm{~h}^{2}}$
Moving Charges & Magnetism

153182 A square conducting loop is placed near an infinitely long current carrying wire with one edge parallel to the wire as shown in the figure. If the current in the straight wire is suddenly halved, which of the following statements will be true?
"The loop will .....".

1 stay stationary
2 move towards the wire
3 move away from the wire
4 move parallel to the wire
Moving Charges & Magnetism

153183 An electric current ' $I$ ' enters and leaves a uniform circular wire of radius $r$ through diametrically opposite points. A particle carrying a charge $q$ moves along the axis of the circular wire with speed $v$. What is the magnetic force experienced by the particle when it passes through the centre of the circle?

1 $\mathrm{qv} \frac{\mu_{0} \mathrm{i}}{\mathrm{a}}$
2 $\mathrm{qv} \frac{\mu_{0} \mathrm{i}}{2 \mathrm{a}}$
3 $\mathrm{qv} \frac{\mu_{0} \mathrm{i}}{2 \pi \mathrm{a}}$
4 Zero
Moving Charges & Magnetism

153184 A very long wire carrying a current $4 \sqrt{2} \mathrm{~A}$ is bent at a right angles. The magnitude of magnetic field $(|\mathrm{B}|)$ at a point $P$ lying on a line perpendicular to the bent wire at a distance, $d$ $=20 \mathrm{~cm}$ from the point of the bending will be (Let $\mu_{0}=4 \pi \times 10^{-7} \mathrm{H} / \mathrm{m}$ )

1 $1 \mu \mathrm{T}$
2 $0.8 \mu \mathrm{T}$
3 $2 \mu \mathrm{T}$
4 $4 \mu \mathrm{T}$
Moving Charges & Magnetism

153185 The magnetic field normal to the plane of a coil of $\mathbf{N}$ turns and radius $\mathbf{r}$ which carries a current $i$ is measured on the axis of the coil at a distance $h$ from the centre of the coil. This is smaller than the field at the centre by the fraction,

1 $\frac{3}{2} \cdot \frac{\mathrm{h}^{2}}{\mathrm{r}^{2}}$
2 $\frac{2}{3} \cdot \frac{\mathrm{h}^{2}}{\mathrm{r}^{2}}$
3 $\frac{3}{2} \cdot \frac{\mathrm{r}^{2}}{\mathrm{~h}^{2}}$
4 $\frac{2}{3} \cdot \frac{\mathrm{r}^{2}}{\mathrm{~h}^{2}}$
Moving Charges & Magnetism

153182 A square conducting loop is placed near an infinitely long current carrying wire with one edge parallel to the wire as shown in the figure. If the current in the straight wire is suddenly halved, which of the following statements will be true?
"The loop will .....".

1 stay stationary
2 move towards the wire
3 move away from the wire
4 move parallel to the wire
Moving Charges & Magnetism

153183 An electric current ' $I$ ' enters and leaves a uniform circular wire of radius $r$ through diametrically opposite points. A particle carrying a charge $q$ moves along the axis of the circular wire with speed $v$. What is the magnetic force experienced by the particle when it passes through the centre of the circle?

1 $\mathrm{qv} \frac{\mu_{0} \mathrm{i}}{\mathrm{a}}$
2 $\mathrm{qv} \frac{\mu_{0} \mathrm{i}}{2 \mathrm{a}}$
3 $\mathrm{qv} \frac{\mu_{0} \mathrm{i}}{2 \pi \mathrm{a}}$
4 Zero
Moving Charges & Magnetism

153184 A very long wire carrying a current $4 \sqrt{2} \mathrm{~A}$ is bent at a right angles. The magnitude of magnetic field $(|\mathrm{B}|)$ at a point $P$ lying on a line perpendicular to the bent wire at a distance, $d$ $=20 \mathrm{~cm}$ from the point of the bending will be (Let $\mu_{0}=4 \pi \times 10^{-7} \mathrm{H} / \mathrm{m}$ )

1 $1 \mu \mathrm{T}$
2 $0.8 \mu \mathrm{T}$
3 $2 \mu \mathrm{T}$
4 $4 \mu \mathrm{T}$
Moving Charges & Magnetism

153185 The magnetic field normal to the plane of a coil of $\mathbf{N}$ turns and radius $\mathbf{r}$ which carries a current $i$ is measured on the axis of the coil at a distance $h$ from the centre of the coil. This is smaller than the field at the centre by the fraction,

1 $\frac{3}{2} \cdot \frac{\mathrm{h}^{2}}{\mathrm{r}^{2}}$
2 $\frac{2}{3} \cdot \frac{\mathrm{h}^{2}}{\mathrm{r}^{2}}$
3 $\frac{3}{2} \cdot \frac{\mathrm{r}^{2}}{\mathrm{~h}^{2}}$
4 $\frac{2}{3} \cdot \frac{\mathrm{r}^{2}}{\mathrm{~h}^{2}}$