The magnetic potential energy when a magnetic bar with a magnetic moment \(\vec{M}\) is placed perpendicular to the magnetic field \(\vec{B}\) is:
1. \(\dfrac{-mB}{2}\) 2. zero
3. \(-mB\) 4. \(mB\)
Subtopic:  Analogy between Electrostatics & Magnetostatics |
 75%
Level 2: 60%+
NEET - 2024
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The magnetic moment of an iron bar is \(M.\) It is now bent in such a way that it forms an arc section of a circle subtending an angle of \(60^\circ\) at the centre. The magnetic moment of this arc section is:
1. \(\dfrac{3 M}{\pi}\) 2. \(\dfrac{4M}{\pi}\)
3. \(\dfrac{ M}{\pi}\) 4. \(\dfrac{2 M}{\pi}\)
Subtopic:  Bar Magnet |
 77%
Level 2: 60%+
NEET - 2024
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The length of a magnetized iron bar is \(L\) and its magnetic moment is \(M.\) When this bar is bent to form a semicircle its magnetic moment is:
1. \(M\) 2. \(\dfrac{M\pi}{2}\)
3. \( \dfrac{M}{2\pi}\) 4. \(\dfrac{2M}{\pi}\)
Subtopic:  Bar Magnet |
 72%
Level 2: 60%+
NEET - 2024
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In a uniform magnetic field of \(0.049~\text T\), a magnetic needle performs \(20\) complete oscillations in \(5\) seconds as shown. The moment of inertia of the needle is \(9.8 × 10^{-6} ~\text{kg m}^2\). If the magnitude of magnetic moment of the needle is \(x \times 10^{-5 }~\text {Am}^2;\) then the value of '\(x\)' is:
1. \(128\pi^2\) 2. \(50\pi^2\)
3. \(1280\pi^2\) 4. \(5\pi^2\)
Subtopic:  Bar Magnet |
 52%
Level 3: 35%-60%
NEET - 2024
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An iron bar of length \( L\) has a magnetic moment \(M.\) It is bent at the middle of its length such that the two arms make an angle \(60^\circ\) with each other. The magnetic moment of this new magnet is:
1. \(\dfrac{M}{2}\) 2. \({2 M}\)
3. \(\dfrac{{M}}{\sqrt{3}}\) 4. \(M\)
Subtopic:  Bar Magnet |
 53%
Level 3: 35%-60%
NEET - 2024
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The following figures show the arrangement of bar magnets in different configurations. Each magnet has a magnetic dipole. Which configuration has the highest net magnetic dipole moment?

1. 2.
3. 4.
Subtopic:  Bar Magnet |
 71%
Level 2: 60%+
AIPMT - 2014
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A bar magnet of the magnetic moment \(M\) is placed at right angles to a magnetic induction \(B.\) If a force \(F\) is experienced by each pole of the magnet, the length of the magnet will be:
1. \(\dfrac{MB}{F}\) 2. \(\dfrac{BF}{M}\)
3. \(\dfrac{MF}{B}\) 4. \(\dfrac{F}{MB}\)
Subtopic:  Bar Magnet |
 75%
Level 2: 60%+
NEET - 2013
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A bar magnet of length \(l\) and magnetic dipole moment \(M\) is bent in the form of an arc as shown in the figure. The new magnetic dipole moment will be:

1. \(\dfrac{3M}{\pi}\) 2. \(\dfrac{2M}{l\pi}\)
3. \(\dfrac{M}{ 2}\) 4. \(M\)
Subtopic:  Bar Magnet |
 82%
Level 1: 80%+
AIPMT - 2013
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The net magnetic flux through any closed surface is:
1. negative 2. zero
3. positive 4. infinity
Subtopic:  Analogy between Electrostatics & Magnetostatics |
 87%
Level 1: 80%+
NEET - 2023
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Given below are two statements:
Assertion (A): Gauss's law for magnetism states that the net magnetic flux through any closed surface is zero.
Reason (R): The magnetic monopoles do not exist. North and South poles occur in pairs, allowing vanishing net magnetic flux through the surface.
 
1. (A) is True but (R) is False.
2. (A) is False but (R) is True.
3. Both (A) and (R) are True and (R) is the correct explanation of (A).
4. Both (A) and (R) are True but (R) is not the correct explanation of (A).
Subtopic:  Analogy between Electrostatics & Magnetostatics |
 77%
Level 2: 60%+
NEET - 2022
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