00. Magnet and Magnetic Dipole
Magnetism and Matter

154079 Two identical short bar magnets each having magnetic moment $M$ are placed at a distance of 2d with their axes perpendicular to each other in a horizontal plane. The magnetic induction at mid point between them is:

1 $\frac{\mu_{0}}{4 \pi} \sqrt{2} \frac{\mathrm{M}}{\mathrm{d}^{3}}$
2 $\frac{\mu_{0}}{4 \pi} \sqrt{3} \frac{M}{d^{3}}$
3 $2 \frac{\mu_{0}}{\pi} \frac{M}{\mathrm{~d}^{3}}$
4 $\frac{\mu_{0}}{4 \pi} \sqrt{5} \frac{\mathrm{M}}{\mathrm{d}^{3}}$
Magnetism and Matter

154080 Two short bar magnets having magnetic moments in the ratio $27: 8$, when placed on opposite sides of a deflection magnetometer. It shows no deflection. If the distance of the weaker magnet is $0.12 \mathrm{~m}$ from the centre of deflection magnetometer the distance of the stronger magnet from the centre is:

1 $0.06 \mathrm{~m}$
2 $0.08 \mathrm{~m}$
3 $0.12 \mathrm{~m}$
4 $0.18 \mathrm{~m}$
Magnetism and Matter

154082 If two bar magnets of different magnetic lengths have equal moments, then the pole strength is:

1 equal for both the magnets
2 lesser for shorter magnet
3 more for longer magnet
4 more for shorter magnet
Magnetism and Matter

154084 A barmagnet of pole strength $2 \mathrm{~A}-\mathrm{m}$ is kept in a magnetic field of induction $4 \times 10^{-5} \mathrm{~Wb} / \mathrm{m}^{2}$ such that the axis of the magnet makes an angle $30^{\circ}$ with the direction of the field. The couple acting on the magnet is found to be $80 \times 10^{-7} \mathrm{Nm}$. Then, the distance between the poles of the magnet is:

1 $20 \mathrm{~m}$
2 $2 \mathrm{~m}$
3 $3 \mathrm{~cm}$
4 $20 \mathrm{~cm}$
Magnetism and Matter

154086 In a deflection magnetometer experiment in $\tan A$ position, a short bar magnet placed at 18 cm from the centre of the compass needle produces a deflection of $30^{\circ}$. If another magnet of same length but 16 times pole strength as that of first magnet is placed in $\tan B$ position at $36 \mathrm{~cm}$, the deflection will be

1 $0^{\circ}$
2 $30^{\circ}$
3 $45^{\circ}$
4 $60^{\circ}$
Magnetism and Matter

154079 Two identical short bar magnets each having magnetic moment $M$ are placed at a distance of 2d with their axes perpendicular to each other in a horizontal plane. The magnetic induction at mid point between them is:

1 $\frac{\mu_{0}}{4 \pi} \sqrt{2} \frac{\mathrm{M}}{\mathrm{d}^{3}}$
2 $\frac{\mu_{0}}{4 \pi} \sqrt{3} \frac{M}{d^{3}}$
3 $2 \frac{\mu_{0}}{\pi} \frac{M}{\mathrm{~d}^{3}}$
4 $\frac{\mu_{0}}{4 \pi} \sqrt{5} \frac{\mathrm{M}}{\mathrm{d}^{3}}$
Magnetism and Matter

154080 Two short bar magnets having magnetic moments in the ratio $27: 8$, when placed on opposite sides of a deflection magnetometer. It shows no deflection. If the distance of the weaker magnet is $0.12 \mathrm{~m}$ from the centre of deflection magnetometer the distance of the stronger magnet from the centre is:

1 $0.06 \mathrm{~m}$
2 $0.08 \mathrm{~m}$
3 $0.12 \mathrm{~m}$
4 $0.18 \mathrm{~m}$
Magnetism and Matter

154082 If two bar magnets of different magnetic lengths have equal moments, then the pole strength is:

1 equal for both the magnets
2 lesser for shorter magnet
3 more for longer magnet
4 more for shorter magnet
Magnetism and Matter

154084 A barmagnet of pole strength $2 \mathrm{~A}-\mathrm{m}$ is kept in a magnetic field of induction $4 \times 10^{-5} \mathrm{~Wb} / \mathrm{m}^{2}$ such that the axis of the magnet makes an angle $30^{\circ}$ with the direction of the field. The couple acting on the magnet is found to be $80 \times 10^{-7} \mathrm{Nm}$. Then, the distance between the poles of the magnet is:

1 $20 \mathrm{~m}$
2 $2 \mathrm{~m}$
3 $3 \mathrm{~cm}$
4 $20 \mathrm{~cm}$
Magnetism and Matter

154086 In a deflection magnetometer experiment in $\tan A$ position, a short bar magnet placed at 18 cm from the centre of the compass needle produces a deflection of $30^{\circ}$. If another magnet of same length but 16 times pole strength as that of first magnet is placed in $\tan B$ position at $36 \mathrm{~cm}$, the deflection will be

1 $0^{\circ}$
2 $30^{\circ}$
3 $45^{\circ}$
4 $60^{\circ}$
Magnetism and Matter

154079 Two identical short bar magnets each having magnetic moment $M$ are placed at a distance of 2d with their axes perpendicular to each other in a horizontal plane. The magnetic induction at mid point between them is:

1 $\frac{\mu_{0}}{4 \pi} \sqrt{2} \frac{\mathrm{M}}{\mathrm{d}^{3}}$
2 $\frac{\mu_{0}}{4 \pi} \sqrt{3} \frac{M}{d^{3}}$
3 $2 \frac{\mu_{0}}{\pi} \frac{M}{\mathrm{~d}^{3}}$
4 $\frac{\mu_{0}}{4 \pi} \sqrt{5} \frac{\mathrm{M}}{\mathrm{d}^{3}}$
Magnetism and Matter

154080 Two short bar magnets having magnetic moments in the ratio $27: 8$, when placed on opposite sides of a deflection magnetometer. It shows no deflection. If the distance of the weaker magnet is $0.12 \mathrm{~m}$ from the centre of deflection magnetometer the distance of the stronger magnet from the centre is:

1 $0.06 \mathrm{~m}$
2 $0.08 \mathrm{~m}$
3 $0.12 \mathrm{~m}$
4 $0.18 \mathrm{~m}$
Magnetism and Matter

154082 If two bar magnets of different magnetic lengths have equal moments, then the pole strength is:

1 equal for both the magnets
2 lesser for shorter magnet
3 more for longer magnet
4 more for shorter magnet
Magnetism and Matter

154084 A barmagnet of pole strength $2 \mathrm{~A}-\mathrm{m}$ is kept in a magnetic field of induction $4 \times 10^{-5} \mathrm{~Wb} / \mathrm{m}^{2}$ such that the axis of the magnet makes an angle $30^{\circ}$ with the direction of the field. The couple acting on the magnet is found to be $80 \times 10^{-7} \mathrm{Nm}$. Then, the distance between the poles of the magnet is:

1 $20 \mathrm{~m}$
2 $2 \mathrm{~m}$
3 $3 \mathrm{~cm}$
4 $20 \mathrm{~cm}$
Magnetism and Matter

154086 In a deflection magnetometer experiment in $\tan A$ position, a short bar magnet placed at 18 cm from the centre of the compass needle produces a deflection of $30^{\circ}$. If another magnet of same length but 16 times pole strength as that of first magnet is placed in $\tan B$ position at $36 \mathrm{~cm}$, the deflection will be

1 $0^{\circ}$
2 $30^{\circ}$
3 $45^{\circ}$
4 $60^{\circ}$
Magnetism and Matter

154079 Two identical short bar magnets each having magnetic moment $M$ are placed at a distance of 2d with their axes perpendicular to each other in a horizontal plane. The magnetic induction at mid point between them is:

1 $\frac{\mu_{0}}{4 \pi} \sqrt{2} \frac{\mathrm{M}}{\mathrm{d}^{3}}$
2 $\frac{\mu_{0}}{4 \pi} \sqrt{3} \frac{M}{d^{3}}$
3 $2 \frac{\mu_{0}}{\pi} \frac{M}{\mathrm{~d}^{3}}$
4 $\frac{\mu_{0}}{4 \pi} \sqrt{5} \frac{\mathrm{M}}{\mathrm{d}^{3}}$
Magnetism and Matter

154080 Two short bar magnets having magnetic moments in the ratio $27: 8$, when placed on opposite sides of a deflection magnetometer. It shows no deflection. If the distance of the weaker magnet is $0.12 \mathrm{~m}$ from the centre of deflection magnetometer the distance of the stronger magnet from the centre is:

1 $0.06 \mathrm{~m}$
2 $0.08 \mathrm{~m}$
3 $0.12 \mathrm{~m}$
4 $0.18 \mathrm{~m}$
Magnetism and Matter

154082 If two bar magnets of different magnetic lengths have equal moments, then the pole strength is:

1 equal for both the magnets
2 lesser for shorter magnet
3 more for longer magnet
4 more for shorter magnet
Magnetism and Matter

154084 A barmagnet of pole strength $2 \mathrm{~A}-\mathrm{m}$ is kept in a magnetic field of induction $4 \times 10^{-5} \mathrm{~Wb} / \mathrm{m}^{2}$ such that the axis of the magnet makes an angle $30^{\circ}$ with the direction of the field. The couple acting on the magnet is found to be $80 \times 10^{-7} \mathrm{Nm}$. Then, the distance between the poles of the magnet is:

1 $20 \mathrm{~m}$
2 $2 \mathrm{~m}$
3 $3 \mathrm{~cm}$
4 $20 \mathrm{~cm}$
Magnetism and Matter

154086 In a deflection magnetometer experiment in $\tan A$ position, a short bar magnet placed at 18 cm from the centre of the compass needle produces a deflection of $30^{\circ}$. If another magnet of same length but 16 times pole strength as that of first magnet is placed in $\tan B$ position at $36 \mathrm{~cm}$, the deflection will be

1 $0^{\circ}$
2 $30^{\circ}$
3 $45^{\circ}$
4 $60^{\circ}$
Magnetism and Matter

154079 Two identical short bar magnets each having magnetic moment $M$ are placed at a distance of 2d with their axes perpendicular to each other in a horizontal plane. The magnetic induction at mid point between them is:

1 $\frac{\mu_{0}}{4 \pi} \sqrt{2} \frac{\mathrm{M}}{\mathrm{d}^{3}}$
2 $\frac{\mu_{0}}{4 \pi} \sqrt{3} \frac{M}{d^{3}}$
3 $2 \frac{\mu_{0}}{\pi} \frac{M}{\mathrm{~d}^{3}}$
4 $\frac{\mu_{0}}{4 \pi} \sqrt{5} \frac{\mathrm{M}}{\mathrm{d}^{3}}$
Magnetism and Matter

154080 Two short bar magnets having magnetic moments in the ratio $27: 8$, when placed on opposite sides of a deflection magnetometer. It shows no deflection. If the distance of the weaker magnet is $0.12 \mathrm{~m}$ from the centre of deflection magnetometer the distance of the stronger magnet from the centre is:

1 $0.06 \mathrm{~m}$
2 $0.08 \mathrm{~m}$
3 $0.12 \mathrm{~m}$
4 $0.18 \mathrm{~m}$
Magnetism and Matter

154082 If two bar magnets of different magnetic lengths have equal moments, then the pole strength is:

1 equal for both the magnets
2 lesser for shorter magnet
3 more for longer magnet
4 more for shorter magnet
Magnetism and Matter

154084 A barmagnet of pole strength $2 \mathrm{~A}-\mathrm{m}$ is kept in a magnetic field of induction $4 \times 10^{-5} \mathrm{~Wb} / \mathrm{m}^{2}$ such that the axis of the magnet makes an angle $30^{\circ}$ with the direction of the field. The couple acting on the magnet is found to be $80 \times 10^{-7} \mathrm{Nm}$. Then, the distance between the poles of the magnet is:

1 $20 \mathrm{~m}$
2 $2 \mathrm{~m}$
3 $3 \mathrm{~cm}$
4 $20 \mathrm{~cm}$
Magnetism and Matter

154086 In a deflection magnetometer experiment in $\tan A$ position, a short bar magnet placed at 18 cm from the centre of the compass needle produces a deflection of $30^{\circ}$. If another magnet of same length but 16 times pole strength as that of first magnet is placed in $\tan B$ position at $36 \mathrm{~cm}$, the deflection will be

1 $0^{\circ}$
2 $30^{\circ}$
3 $45^{\circ}$
4 $60^{\circ}$