SATHEE: Magnetism and Matter - Result Question 7

Magnetism and Matter - Result Question 7

10. The work done in turning a magnet of magnetic moment $M$ by an angle of $90^{\circ}$ from the meridian, is $n$ times the corresponding work done to turn it through an angle of $60^{\circ}$ . The value of $n$ is given by

(a) 2

(b) 1

(d) 0.25

[1995]

Topic 2: The Earth’s Magnetism, Magnetic

Materials and their Properties11. An iron rod of susceptibility 599 is subjected to a magnetising field of $1200 A m^{- 1}$ . The permeability of the material of the rod is :

$(μ_{0} = 4 π \times 10^{- 7} T m A^{- 1})$

(a) $8.0 \times 10^{- 5} T m A^{- 1}$

[2020]

(b) $2.4 π \times 10^{- 5} T m A^{- 1}$

(d) $2.4 π \times 10^{- 4} T m A^{- 1}$

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Answer:

Correct Answer: 10. (a)

Solution:

(a) Magnetic moment $= M$ ; Initial angle through which magnet is turned $(θ_{1}) = 90^{\circ}$ and final angle through which magnet is turned $(θ_{2}) =$ $60^{\circ}$ . Work done in turning the magnet through $90^{\circ} (W_{1}) = M B (\cos 0^{\circ} - \cos 90^{\circ})$ $= M B (1 - 0) = M B$ .

Similarly, $W_{2} = M B (\cos 0^{\circ} - \cos 60^{\circ})$

$= M B (1 - \frac{1}{2}) = \frac{M B}{2}$

$∴ W_{1} = 2 W_{2}$ or $n = 2$ .

Magnetism and Matter - Result Question 7

10. The work done in turning a magnet of magnetic moment $M$ by an angle of $90^{\circ}$ from the meridian, is $n$ times the corresponding work done to turn it through an angle of $60^{\circ}$ . The value of $n$ is given by

Topic 2: The Earth’s Magnetism, Magnetic

Answer:

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Magnetism and Matter - Result Question 7

10. The work done in turning a magnet of magnetic moment M by an angle of 90∘ from the meridian, is n times the corresponding work done to turn it through an angle of 60∘. The value of n is given by

Topic 2: The Earth’s Magnetism, Magnetic

Answer:

Engineering Preparation

Medical Preparation

NCERT Books & Solutions

Important Resources

Other Resources

Syllabus

Test Platform

Sample Mock Test

Mentorship

NCERT Exercise Video Solution

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10. The work done in turning a magnet of magnetic moment $M$ by an angle of $90^{\circ}$ from the meridian, is $n$ times the corresponding work done to turn it through an angle of $60^{\circ}$ . The value of $n$ is given by