154038
A bar magnet of magnetic moment $220 \mathrm{Am}^{2}$ is suspended in a magnetic field of intensity 0.25 N/Am. The couple required to deflect it through $3^{\circ}$ is :
1 $27.5 \mathrm{Nm}$
2 $20.25 \mathrm{Nm}$
3 $47.63 \mathrm{Nm}$
4 $12 \mathrm{Nm}$
Explanation:
A Given, magnetic moment (M) $=220 \mathrm{Am}^{2}$, magnetic field intensity $(\mathrm{B})=0.25 \mathrm{~N} / \mathrm{A}-\mathrm{m}$, deflection $(\theta)=30^{\circ}$ We know that, couple $=\mathrm{M} \times \mathrm{B} \sin \theta$ $=220 \times 0.25 \times \sin 30^{\circ}$ $=220 \times 0.25 \times \frac{1}{2}$ Couple $=27.5 \mathrm{Nm}$
JCECE-2003
Magnetism and Matter
154045
The time period of a freely suspended magnet does not depend upon-
1 length of the magnet
2 the pole strength of the magnet
3 The horizontal component of magnetic field of earth
4 the length of the suspension
Explanation:
D Time period of freely suspended magnet $\mathrm{T}=2 \pi \sqrt{\frac{\mathrm{I}}{\mathrm{MB}_{\mathrm{H}}}}$ $\therefore$ I does not depend on the length of suspension $\because \quad \mathrm{I}=\frac{\mathrm{mL}^{2}}{12}$ Where, $\mathrm{L}=$ length of magnet
BCECE-2013
Magnetism and Matter
154050
A metallic rod of length $l$ is placed normal to the magnetic field $B$ and revolved in a circular path about one of the ends with angular frequency $\omega$. The potential difference across the ends will be :
1 $\frac{1}{2} \mathrm{~B}^{2} l \omega$
2 $\frac{1}{2} \mathrm{~B} \omega l^{2}$
3 $\frac{1}{8} \mathrm{~B} \omega l^{2}$
4 $\mathrm{B} \omega l^{2}$
Explanation:
B Given, length of metallic $\operatorname{rod}=l$, magnetic field $=\mathrm{B}$, angular frequency $=\omega$ $\therefore$ Potential difference across eds. $\mathrm{e}=\frac{1}{2} \mathrm{~B} \omega l^{2}$
BCECE-2003
Magnetism and Matter
154054
Consider a short magnetic dipole of magnetic length $10 \mathrm{~cm}$. Its geometric length is
1 $12 \mathrm{~cm}$
2 $8 \mathrm{~cm}$
3 $10 \mathrm{~cm}$
4 $14 \mathrm{~cm}$
Explanation:
A Given, magnetic length $=10 \mathrm{~cm}$ $\because$ Geometric length of magnet is $\frac{6}{5}$ time of its magnetic length. $\therefore$ Geometric length $=\frac{6}{5} \times 10=12 \mathrm{~cm}$
MHT-CET 2005
Magnetism and Matter
154056
The magnetic dipole moment of a current loop is independent of :
1 magnetic field in which it is lying
2 number of turns
3 area of the loop
4 current in the loop
Explanation:
A We know that, Magnetic moment $(\mathrm{M})=$ NIA Where, $\mathrm{A}=$ Area of the coil $\mathrm{N}=$ Number of turns $\mathrm{I}=$ Current in the coil So, the magnetic moment is independent of magnetic field in which it is lying.
154038
A bar magnet of magnetic moment $220 \mathrm{Am}^{2}$ is suspended in a magnetic field of intensity 0.25 N/Am. The couple required to deflect it through $3^{\circ}$ is :
1 $27.5 \mathrm{Nm}$
2 $20.25 \mathrm{Nm}$
3 $47.63 \mathrm{Nm}$
4 $12 \mathrm{Nm}$
Explanation:
A Given, magnetic moment (M) $=220 \mathrm{Am}^{2}$, magnetic field intensity $(\mathrm{B})=0.25 \mathrm{~N} / \mathrm{A}-\mathrm{m}$, deflection $(\theta)=30^{\circ}$ We know that, couple $=\mathrm{M} \times \mathrm{B} \sin \theta$ $=220 \times 0.25 \times \sin 30^{\circ}$ $=220 \times 0.25 \times \frac{1}{2}$ Couple $=27.5 \mathrm{Nm}$
JCECE-2003
Magnetism and Matter
154045
The time period of a freely suspended magnet does not depend upon-
1 length of the magnet
2 the pole strength of the magnet
3 The horizontal component of magnetic field of earth
4 the length of the suspension
Explanation:
D Time period of freely suspended magnet $\mathrm{T}=2 \pi \sqrt{\frac{\mathrm{I}}{\mathrm{MB}_{\mathrm{H}}}}$ $\therefore$ I does not depend on the length of suspension $\because \quad \mathrm{I}=\frac{\mathrm{mL}^{2}}{12}$ Where, $\mathrm{L}=$ length of magnet
BCECE-2013
Magnetism and Matter
154050
A metallic rod of length $l$ is placed normal to the magnetic field $B$ and revolved in a circular path about one of the ends with angular frequency $\omega$. The potential difference across the ends will be :
1 $\frac{1}{2} \mathrm{~B}^{2} l \omega$
2 $\frac{1}{2} \mathrm{~B} \omega l^{2}$
3 $\frac{1}{8} \mathrm{~B} \omega l^{2}$
4 $\mathrm{B} \omega l^{2}$
Explanation:
B Given, length of metallic $\operatorname{rod}=l$, magnetic field $=\mathrm{B}$, angular frequency $=\omega$ $\therefore$ Potential difference across eds. $\mathrm{e}=\frac{1}{2} \mathrm{~B} \omega l^{2}$
BCECE-2003
Magnetism and Matter
154054
Consider a short magnetic dipole of magnetic length $10 \mathrm{~cm}$. Its geometric length is
1 $12 \mathrm{~cm}$
2 $8 \mathrm{~cm}$
3 $10 \mathrm{~cm}$
4 $14 \mathrm{~cm}$
Explanation:
A Given, magnetic length $=10 \mathrm{~cm}$ $\because$ Geometric length of magnet is $\frac{6}{5}$ time of its magnetic length. $\therefore$ Geometric length $=\frac{6}{5} \times 10=12 \mathrm{~cm}$
MHT-CET 2005
Magnetism and Matter
154056
The magnetic dipole moment of a current loop is independent of :
1 magnetic field in which it is lying
2 number of turns
3 area of the loop
4 current in the loop
Explanation:
A We know that, Magnetic moment $(\mathrm{M})=$ NIA Where, $\mathrm{A}=$ Area of the coil $\mathrm{N}=$ Number of turns $\mathrm{I}=$ Current in the coil So, the magnetic moment is independent of magnetic field in which it is lying.
154038
A bar magnet of magnetic moment $220 \mathrm{Am}^{2}$ is suspended in a magnetic field of intensity 0.25 N/Am. The couple required to deflect it through $3^{\circ}$ is :
1 $27.5 \mathrm{Nm}$
2 $20.25 \mathrm{Nm}$
3 $47.63 \mathrm{Nm}$
4 $12 \mathrm{Nm}$
Explanation:
A Given, magnetic moment (M) $=220 \mathrm{Am}^{2}$, magnetic field intensity $(\mathrm{B})=0.25 \mathrm{~N} / \mathrm{A}-\mathrm{m}$, deflection $(\theta)=30^{\circ}$ We know that, couple $=\mathrm{M} \times \mathrm{B} \sin \theta$ $=220 \times 0.25 \times \sin 30^{\circ}$ $=220 \times 0.25 \times \frac{1}{2}$ Couple $=27.5 \mathrm{Nm}$
JCECE-2003
Magnetism and Matter
154045
The time period of a freely suspended magnet does not depend upon-
1 length of the magnet
2 the pole strength of the magnet
3 The horizontal component of magnetic field of earth
4 the length of the suspension
Explanation:
D Time period of freely suspended magnet $\mathrm{T}=2 \pi \sqrt{\frac{\mathrm{I}}{\mathrm{MB}_{\mathrm{H}}}}$ $\therefore$ I does not depend on the length of suspension $\because \quad \mathrm{I}=\frac{\mathrm{mL}^{2}}{12}$ Where, $\mathrm{L}=$ length of magnet
BCECE-2013
Magnetism and Matter
154050
A metallic rod of length $l$ is placed normal to the magnetic field $B$ and revolved in a circular path about one of the ends with angular frequency $\omega$. The potential difference across the ends will be :
1 $\frac{1}{2} \mathrm{~B}^{2} l \omega$
2 $\frac{1}{2} \mathrm{~B} \omega l^{2}$
3 $\frac{1}{8} \mathrm{~B} \omega l^{2}$
4 $\mathrm{B} \omega l^{2}$
Explanation:
B Given, length of metallic $\operatorname{rod}=l$, magnetic field $=\mathrm{B}$, angular frequency $=\omega$ $\therefore$ Potential difference across eds. $\mathrm{e}=\frac{1}{2} \mathrm{~B} \omega l^{2}$
BCECE-2003
Magnetism and Matter
154054
Consider a short magnetic dipole of magnetic length $10 \mathrm{~cm}$. Its geometric length is
1 $12 \mathrm{~cm}$
2 $8 \mathrm{~cm}$
3 $10 \mathrm{~cm}$
4 $14 \mathrm{~cm}$
Explanation:
A Given, magnetic length $=10 \mathrm{~cm}$ $\because$ Geometric length of magnet is $\frac{6}{5}$ time of its magnetic length. $\therefore$ Geometric length $=\frac{6}{5} \times 10=12 \mathrm{~cm}$
MHT-CET 2005
Magnetism and Matter
154056
The magnetic dipole moment of a current loop is independent of :
1 magnetic field in which it is lying
2 number of turns
3 area of the loop
4 current in the loop
Explanation:
A We know that, Magnetic moment $(\mathrm{M})=$ NIA Where, $\mathrm{A}=$ Area of the coil $\mathrm{N}=$ Number of turns $\mathrm{I}=$ Current in the coil So, the magnetic moment is independent of magnetic field in which it is lying.
154038
A bar magnet of magnetic moment $220 \mathrm{Am}^{2}$ is suspended in a magnetic field of intensity 0.25 N/Am. The couple required to deflect it through $3^{\circ}$ is :
1 $27.5 \mathrm{Nm}$
2 $20.25 \mathrm{Nm}$
3 $47.63 \mathrm{Nm}$
4 $12 \mathrm{Nm}$
Explanation:
A Given, magnetic moment (M) $=220 \mathrm{Am}^{2}$, magnetic field intensity $(\mathrm{B})=0.25 \mathrm{~N} / \mathrm{A}-\mathrm{m}$, deflection $(\theta)=30^{\circ}$ We know that, couple $=\mathrm{M} \times \mathrm{B} \sin \theta$ $=220 \times 0.25 \times \sin 30^{\circ}$ $=220 \times 0.25 \times \frac{1}{2}$ Couple $=27.5 \mathrm{Nm}$
JCECE-2003
Magnetism and Matter
154045
The time period of a freely suspended magnet does not depend upon-
1 length of the magnet
2 the pole strength of the magnet
3 The horizontal component of magnetic field of earth
4 the length of the suspension
Explanation:
D Time period of freely suspended magnet $\mathrm{T}=2 \pi \sqrt{\frac{\mathrm{I}}{\mathrm{MB}_{\mathrm{H}}}}$ $\therefore$ I does not depend on the length of suspension $\because \quad \mathrm{I}=\frac{\mathrm{mL}^{2}}{12}$ Where, $\mathrm{L}=$ length of magnet
BCECE-2013
Magnetism and Matter
154050
A metallic rod of length $l$ is placed normal to the magnetic field $B$ and revolved in a circular path about one of the ends with angular frequency $\omega$. The potential difference across the ends will be :
1 $\frac{1}{2} \mathrm{~B}^{2} l \omega$
2 $\frac{1}{2} \mathrm{~B} \omega l^{2}$
3 $\frac{1}{8} \mathrm{~B} \omega l^{2}$
4 $\mathrm{B} \omega l^{2}$
Explanation:
B Given, length of metallic $\operatorname{rod}=l$, magnetic field $=\mathrm{B}$, angular frequency $=\omega$ $\therefore$ Potential difference across eds. $\mathrm{e}=\frac{1}{2} \mathrm{~B} \omega l^{2}$
BCECE-2003
Magnetism and Matter
154054
Consider a short magnetic dipole of magnetic length $10 \mathrm{~cm}$. Its geometric length is
1 $12 \mathrm{~cm}$
2 $8 \mathrm{~cm}$
3 $10 \mathrm{~cm}$
4 $14 \mathrm{~cm}$
Explanation:
A Given, magnetic length $=10 \mathrm{~cm}$ $\because$ Geometric length of magnet is $\frac{6}{5}$ time of its magnetic length. $\therefore$ Geometric length $=\frac{6}{5} \times 10=12 \mathrm{~cm}$
MHT-CET 2005
Magnetism and Matter
154056
The magnetic dipole moment of a current loop is independent of :
1 magnetic field in which it is lying
2 number of turns
3 area of the loop
4 current in the loop
Explanation:
A We know that, Magnetic moment $(\mathrm{M})=$ NIA Where, $\mathrm{A}=$ Area of the coil $\mathrm{N}=$ Number of turns $\mathrm{I}=$ Current in the coil So, the magnetic moment is independent of magnetic field in which it is lying.
154038
A bar magnet of magnetic moment $220 \mathrm{Am}^{2}$ is suspended in a magnetic field of intensity 0.25 N/Am. The couple required to deflect it through $3^{\circ}$ is :
1 $27.5 \mathrm{Nm}$
2 $20.25 \mathrm{Nm}$
3 $47.63 \mathrm{Nm}$
4 $12 \mathrm{Nm}$
Explanation:
A Given, magnetic moment (M) $=220 \mathrm{Am}^{2}$, magnetic field intensity $(\mathrm{B})=0.25 \mathrm{~N} / \mathrm{A}-\mathrm{m}$, deflection $(\theta)=30^{\circ}$ We know that, couple $=\mathrm{M} \times \mathrm{B} \sin \theta$ $=220 \times 0.25 \times \sin 30^{\circ}$ $=220 \times 0.25 \times \frac{1}{2}$ Couple $=27.5 \mathrm{Nm}$
JCECE-2003
Magnetism and Matter
154045
The time period of a freely suspended magnet does not depend upon-
1 length of the magnet
2 the pole strength of the magnet
3 The horizontal component of magnetic field of earth
4 the length of the suspension
Explanation:
D Time period of freely suspended magnet $\mathrm{T}=2 \pi \sqrt{\frac{\mathrm{I}}{\mathrm{MB}_{\mathrm{H}}}}$ $\therefore$ I does not depend on the length of suspension $\because \quad \mathrm{I}=\frac{\mathrm{mL}^{2}}{12}$ Where, $\mathrm{L}=$ length of magnet
BCECE-2013
Magnetism and Matter
154050
A metallic rod of length $l$ is placed normal to the magnetic field $B$ and revolved in a circular path about one of the ends with angular frequency $\omega$. The potential difference across the ends will be :
1 $\frac{1}{2} \mathrm{~B}^{2} l \omega$
2 $\frac{1}{2} \mathrm{~B} \omega l^{2}$
3 $\frac{1}{8} \mathrm{~B} \omega l^{2}$
4 $\mathrm{B} \omega l^{2}$
Explanation:
B Given, length of metallic $\operatorname{rod}=l$, magnetic field $=\mathrm{B}$, angular frequency $=\omega$ $\therefore$ Potential difference across eds. $\mathrm{e}=\frac{1}{2} \mathrm{~B} \omega l^{2}$
BCECE-2003
Magnetism and Matter
154054
Consider a short magnetic dipole of magnetic length $10 \mathrm{~cm}$. Its geometric length is
1 $12 \mathrm{~cm}$
2 $8 \mathrm{~cm}$
3 $10 \mathrm{~cm}$
4 $14 \mathrm{~cm}$
Explanation:
A Given, magnetic length $=10 \mathrm{~cm}$ $\because$ Geometric length of magnet is $\frac{6}{5}$ time of its magnetic length. $\therefore$ Geometric length $=\frac{6}{5} \times 10=12 \mathrm{~cm}$
MHT-CET 2005
Magnetism and Matter
154056
The magnetic dipole moment of a current loop is independent of :
1 magnetic field in which it is lying
2 number of turns
3 area of the loop
4 current in the loop
Explanation:
A We know that, Magnetic moment $(\mathrm{M})=$ NIA Where, $\mathrm{A}=$ Area of the coil $\mathrm{N}=$ Number of turns $\mathrm{I}=$ Current in the coil So, the magnetic moment is independent of magnetic field in which it is lying.
