Q49. A bar magnet of magnetic moment 3J/T lies aligned with the directions of a uniform magnetic fie

Q: What is the correct answer for CUET UG Physics Q49?

The correct answer is a. The potential energy (U) of a magnetic dipole with magnetic moment (M) in a uniform magnetic field (B) is given by U = -M⋅B = -MBcosθ, where θ is the angle between the magnetic moment and the magnetic field. The work done (W) required to change the orientation of the magnetic dipole from an initial angle θ₁ to a final angle θ₂ is W = U_final - U_initial = -MB(cosθ₂ - cosθ₁). Given magnetic moment

Q: Q49. A bar magnet of magnetic moment 3J/T lies aligned with the directions of a uniform magnetic field of 0.2 T. The amount of work, required so as to align its magnetic moment opposite to the field…

The correct answer is a. The potential energy (U) of a magnetic dipole with magnetic moment (M) in a uniform magnetic field (B) is given by U = -M⋅B = -MBcosθ, where θ is the angle between the magnetic moment and the magnetic field. The work done (W) required to change the orientation of the magnetic dipole from an initial angle θ₁ to a final angle θ₂ is W = U_final - U_initial = -MB(cosθ₂ - cosθ₁). Given magnetic moment

Q: What are the options for this CUET UG Physics question?

A. 1.2 J · B. 0.6 J · C. zero · D. -0.6 J

Question

Q49. A bar magnet of magnetic moment 3J/T lies aligned with the directions of a uniform magnetic field of 0.2 T. The amount of work, required so as to align its magnetic moment opposite to the field direction is:
(a) 1.2 J
(b) 0.6 J
(c) zero
(d) -0.6 J

FirstInTest · Accepted Answer

The potential energy (U) of a magnetic dipole with magnetic moment (M) in a uniform magnetic field (B) is given by U = -M⋅B = -MBcosθ, where θ is the angle between the magnetic moment and the magnetic field. The work done (W) required to change the orientation of the magnetic dipole from an initial angle θ₁ to a final angle θ₂ is W = U_final - U_initial = -MB(cosθ₂ - cosθ₁). Given magnetic moment M = 3 J/T and magnetic field B = 0.2 T. Initially, the magnet is aligned with the field, so θ₁ = 0°. Finally, it is aligned opposite to the field, so θ₂ = 180°. Substituting these values: W = -(3 J/T)(0.2 T)(cos(180°) - cos(0°)). W = -0.6 J(-1 - 1) = -0.6 J(-2) = 1.2 J. Therefore, the work required is 1.2 J.

Answer

1.2 J

Answer

0.6 J

Answer

zero

Answer

-0.6 J

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