153210
Which one of the following statements about magnetic field lines is NOT correct?
1 They can emanate from a point
2 They do not cross each other
3 Field lines between two poles cannot be precisely straight lines at the ends
4 There are no field lines within a bar magnet
Explanation:
D The imaginary lines which represent the direction of the magnetic field are called as magnetic field lines. Magnetic monopoles never exist alone due to which the magnetic field lines cannot emanate from a point or terminate at a point. Therefore, field line exist within a bar magnet. Hence, option (d) is not correct.
NDA (I) 2018
Moving Charges & Magnetism
153216
A very long straight wire of radius $r$ carries current $I$. Intensity of magnetic field $B$ at a point, lying at a perpendicular distance ' $a$ ' from the axis is $\propto$
1 $\mathrm{a}^{2}$
2 $\frac{1}{a^{2}}$
3 $\frac{1}{\mathrm{a}}$
4 $\mathrm{a}$
Explanation:
C Magnetic field due to a very long current carrying wire of radius $r$ at perpendicular distance $a$. $\mathrm{B}=\frac{\mu_{0} \mathrm{I}}{2 \pi \mathrm{a}}$ $\mathrm{B} \propto \frac{1}{\mathrm{a}}$
GUJCET 2018
Moving Charges & Magnetism
153225
The intensity of magnetic field due to current $I$ in a long straight wire is proportional to
1 I
2 $\mathrm{I}^{2}$
3 $\sqrt{\mathrm{I}}$
4 $\frac{1}{\mathrm{I}}$
Explanation:
A Magnetic field due to current I in a long wire is given as- $\mathrm{B}=\frac{\mu_{0} \mathrm{I}}{2 \pi \mathrm{r}}$ $\mathrm{B} \propto \mathrm{I}$
CG PET -2018
Moving Charges & Magnetism
153232
1 A current flows through an infinitely long straight wire. The magnetic field produced at a point $1 \mathrm{~m}$ away from it is
1 $2 \times 10^{-3} \mathrm{~T}$
2 $\frac{2}{10} \mathrm{~T}$
3 $2 \times 10^{-7} \mathrm{~T}$
4 $2 \pi \times 10^{-6} \mathrm{~T}$
Explanation:
C Current in the wire I = $1 \mathrm{~A}$ Magnetic field due to infinitely long straight wire carrying current $I$ at a distance $\mathrm{d}=1 \mathrm{~m}$ from it. $\mathrm{B}=\frac{\mu_{0} \mathrm{I}}{2 \pi \mathrm{d}}=\frac{4 \pi \times 10^{-7}}{2 \pi} \times \frac{1}{1}$ $\mathrm{~B}=2 \times 10^{-7} \mathrm{~T}$
NEET Test Series from KOTA - 10 Papers In MS WORD
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Moving Charges & Magnetism
153210
Which one of the following statements about magnetic field lines is NOT correct?
1 They can emanate from a point
2 They do not cross each other
3 Field lines between two poles cannot be precisely straight lines at the ends
4 There are no field lines within a bar magnet
Explanation:
D The imaginary lines which represent the direction of the magnetic field are called as magnetic field lines. Magnetic monopoles never exist alone due to which the magnetic field lines cannot emanate from a point or terminate at a point. Therefore, field line exist within a bar magnet. Hence, option (d) is not correct.
NDA (I) 2018
Moving Charges & Magnetism
153216
A very long straight wire of radius $r$ carries current $I$. Intensity of magnetic field $B$ at a point, lying at a perpendicular distance ' $a$ ' from the axis is $\propto$
1 $\mathrm{a}^{2}$
2 $\frac{1}{a^{2}}$
3 $\frac{1}{\mathrm{a}}$
4 $\mathrm{a}$
Explanation:
C Magnetic field due to a very long current carrying wire of radius $r$ at perpendicular distance $a$. $\mathrm{B}=\frac{\mu_{0} \mathrm{I}}{2 \pi \mathrm{a}}$ $\mathrm{B} \propto \frac{1}{\mathrm{a}}$
GUJCET 2018
Moving Charges & Magnetism
153225
The intensity of magnetic field due to current $I$ in a long straight wire is proportional to
1 I
2 $\mathrm{I}^{2}$
3 $\sqrt{\mathrm{I}}$
4 $\frac{1}{\mathrm{I}}$
Explanation:
A Magnetic field due to current I in a long wire is given as- $\mathrm{B}=\frac{\mu_{0} \mathrm{I}}{2 \pi \mathrm{r}}$ $\mathrm{B} \propto \mathrm{I}$
CG PET -2018
Moving Charges & Magnetism
153232
1 A current flows through an infinitely long straight wire. The magnetic field produced at a point $1 \mathrm{~m}$ away from it is
1 $2 \times 10^{-3} \mathrm{~T}$
2 $\frac{2}{10} \mathrm{~T}$
3 $2 \times 10^{-7} \mathrm{~T}$
4 $2 \pi \times 10^{-6} \mathrm{~T}$
Explanation:
C Current in the wire I = $1 \mathrm{~A}$ Magnetic field due to infinitely long straight wire carrying current $I$ at a distance $\mathrm{d}=1 \mathrm{~m}$ from it. $\mathrm{B}=\frac{\mu_{0} \mathrm{I}}{2 \pi \mathrm{d}}=\frac{4 \pi \times 10^{-7}}{2 \pi} \times \frac{1}{1}$ $\mathrm{~B}=2 \times 10^{-7} \mathrm{~T}$
153210
Which one of the following statements about magnetic field lines is NOT correct?
1 They can emanate from a point
2 They do not cross each other
3 Field lines between two poles cannot be precisely straight lines at the ends
4 There are no field lines within a bar magnet
Explanation:
D The imaginary lines which represent the direction of the magnetic field are called as magnetic field lines. Magnetic monopoles never exist alone due to which the magnetic field lines cannot emanate from a point or terminate at a point. Therefore, field line exist within a bar magnet. Hence, option (d) is not correct.
NDA (I) 2018
Moving Charges & Magnetism
153216
A very long straight wire of radius $r$ carries current $I$. Intensity of magnetic field $B$ at a point, lying at a perpendicular distance ' $a$ ' from the axis is $\propto$
1 $\mathrm{a}^{2}$
2 $\frac{1}{a^{2}}$
3 $\frac{1}{\mathrm{a}}$
4 $\mathrm{a}$
Explanation:
C Magnetic field due to a very long current carrying wire of radius $r$ at perpendicular distance $a$. $\mathrm{B}=\frac{\mu_{0} \mathrm{I}}{2 \pi \mathrm{a}}$ $\mathrm{B} \propto \frac{1}{\mathrm{a}}$
GUJCET 2018
Moving Charges & Magnetism
153225
The intensity of magnetic field due to current $I$ in a long straight wire is proportional to
1 I
2 $\mathrm{I}^{2}$
3 $\sqrt{\mathrm{I}}$
4 $\frac{1}{\mathrm{I}}$
Explanation:
A Magnetic field due to current I in a long wire is given as- $\mathrm{B}=\frac{\mu_{0} \mathrm{I}}{2 \pi \mathrm{r}}$ $\mathrm{B} \propto \mathrm{I}$
CG PET -2018
Moving Charges & Magnetism
153232
1 A current flows through an infinitely long straight wire. The magnetic field produced at a point $1 \mathrm{~m}$ away from it is
1 $2 \times 10^{-3} \mathrm{~T}$
2 $\frac{2}{10} \mathrm{~T}$
3 $2 \times 10^{-7} \mathrm{~T}$
4 $2 \pi \times 10^{-6} \mathrm{~T}$
Explanation:
C Current in the wire I = $1 \mathrm{~A}$ Magnetic field due to infinitely long straight wire carrying current $I$ at a distance $\mathrm{d}=1 \mathrm{~m}$ from it. $\mathrm{B}=\frac{\mu_{0} \mathrm{I}}{2 \pi \mathrm{d}}=\frac{4 \pi \times 10^{-7}}{2 \pi} \times \frac{1}{1}$ $\mathrm{~B}=2 \times 10^{-7} \mathrm{~T}$
153210
Which one of the following statements about magnetic field lines is NOT correct?
1 They can emanate from a point
2 They do not cross each other
3 Field lines between two poles cannot be precisely straight lines at the ends
4 There are no field lines within a bar magnet
Explanation:
D The imaginary lines which represent the direction of the magnetic field are called as magnetic field lines. Magnetic monopoles never exist alone due to which the magnetic field lines cannot emanate from a point or terminate at a point. Therefore, field line exist within a bar magnet. Hence, option (d) is not correct.
NDA (I) 2018
Moving Charges & Magnetism
153216
A very long straight wire of radius $r$ carries current $I$. Intensity of magnetic field $B$ at a point, lying at a perpendicular distance ' $a$ ' from the axis is $\propto$
1 $\mathrm{a}^{2}$
2 $\frac{1}{a^{2}}$
3 $\frac{1}{\mathrm{a}}$
4 $\mathrm{a}$
Explanation:
C Magnetic field due to a very long current carrying wire of radius $r$ at perpendicular distance $a$. $\mathrm{B}=\frac{\mu_{0} \mathrm{I}}{2 \pi \mathrm{a}}$ $\mathrm{B} \propto \frac{1}{\mathrm{a}}$
GUJCET 2018
Moving Charges & Magnetism
153225
The intensity of magnetic field due to current $I$ in a long straight wire is proportional to
1 I
2 $\mathrm{I}^{2}$
3 $\sqrt{\mathrm{I}}$
4 $\frac{1}{\mathrm{I}}$
Explanation:
A Magnetic field due to current I in a long wire is given as- $\mathrm{B}=\frac{\mu_{0} \mathrm{I}}{2 \pi \mathrm{r}}$ $\mathrm{B} \propto \mathrm{I}$
CG PET -2018
Moving Charges & Magnetism
153232
1 A current flows through an infinitely long straight wire. The magnetic field produced at a point $1 \mathrm{~m}$ away from it is
1 $2 \times 10^{-3} \mathrm{~T}$
2 $\frac{2}{10} \mathrm{~T}$
3 $2 \times 10^{-7} \mathrm{~T}$
4 $2 \pi \times 10^{-6} \mathrm{~T}$
Explanation:
C Current in the wire I = $1 \mathrm{~A}$ Magnetic field due to infinitely long straight wire carrying current $I$ at a distance $\mathrm{d}=1 \mathrm{~m}$ from it. $\mathrm{B}=\frac{\mu_{0} \mathrm{I}}{2 \pi \mathrm{d}}=\frac{4 \pi \times 10^{-7}}{2 \pi} \times \frac{1}{1}$ $\mathrm{~B}=2 \times 10^{-7} \mathrm{~T}$
