A bar magnet of length l and magnetic dipole moment M is bent to form an arc which subtends an angle of $120°$ at centre. The new magnetic dipole moment will be

1.  $\frac{3\mathrm{M}}{2\mathrm{\pi }}$

2.  $\frac{3\sqrt{3}\mathrm{M}}{2\mathrm{\pi }}$

3.  $\frac{3\mathrm{M}}{\mathrm{\pi }}$

4.  $\frac{2\mathrm{M}}{\mathrm{\pi }}$

Concept Questions :-

Bar magnet
High Yielding Test Series + Question Bank - NEET 2020

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Concept Questions :-

Earth's magnetism
High Yielding Test Series + Question Bank - NEET 2020

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The unit of pole strength is

(1) $A{m}^{2}$

(2) Am

(3) $\frac{{A}^{2}}{m}$

(4) $\frac{{A}^{2}}{{m}^{2}}$

Concept Questions :-

Bar magnet
High Yielding Test Series + Question Bank - NEET 2020

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Magnetic field lines

1. Cannot intersect

2. Are always closed curves

3. Can pass through vacuum

4. All of these

Concept Questions :-

Magnetic field and field lines
High Yielding Test Series + Question Bank - NEET 2020

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1.

2.

3.

4.  ${\mathrm{tan}}^{-1}\left(\frac{2}{\sqrt{3}}\right)$

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Earth's magnetism
High Yielding Test Series + Question Bank - NEET 2020

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Two small bar magnets are placed in air at a distance r apart. The magnetic force between them is proportional to

(1) ${r}^{2}$

(2) ${r}^{-2}$

(3) ${r}^{-3}$

(4) ${r}^{-4}$

Concept Questions :-

Analogy between electrostatics and magnetostatics
High Yielding Test Series + Question Bank - NEET 2020

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The vertical component of the earths magnetic field is zero at

(1) Magnetic poles

(2) Magnetic equator

(3) Geographic poles

(4) Geographic equator

Concept Questions :-

Earth's magnetism
High Yielding Test Series + Question Bank - NEET 2020

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A short magnetic dipole is placed at the origin with its dipole movement directed along the x-axis. If magnetic field induction at a point P (r, 0) is B$\stackrel{^}{i}$, the magnetic field induction at point Q(0,2r) will be

(1) $\frac{B}{16}\stackrel{^}{i}$

(2) $-\frac{B}{8}\stackrel{^}{j}$

(3) $\frac{B}{16}\stackrel{^}{j}$

(4) $-\frac{B}{16}\stackrel{^}{j}$

Concept Questions :-

Analogy between electrostatics and magnetostatics
High Yielding Test Series + Question Bank - NEET 2020

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The magnetic field at a point x on the axis of a small bar magnet is equal to the field at a point y on the equator of the same magnet. The ratio of the distances of x and y from the centre of the magnet is
(a) ${2}^{-3}$

(b) ${2}^{-1}{3}}$

(c) ${2}^{3}$

(d) ${2}^{1}{3}}$

Concept Questions :-

Bar magnet
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A magnet of magnetic moment 20 C.G.S. units are freely suspended in a uniform magnetic field of intensity 0.3 C.G.S. units. The amount of work done in deflecting it by an angle of ${30}^{o}$ in C.G.S. units is
(a) 6

(b) $3\sqrt{3}$

(c) $3\left(2-\sqrt{3}\right)$

(d) 3

Concept Questions :-

Analogy between electrostatics and magnetostatics