CameraIcon
CameraIcon
SearchIcon
MyQuestionIcon
MyQuestionIcon
Question

A current loop in a magnetic field:


A

can be in equilibrium in one orientation

No worries! We‘ve got your back. Try BYJU‘S free classes today!
B

can be in equilibrium in two orientations, both the equilibrium states are unstable

No worries! We‘ve got your back. Try BYJU‘S free classes today!
C

can be in equilibrium in two orientations, one is stable while the other is unstable

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
D

experiences a torque where the field is uniform or non-uniform in all orientations.

No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is C

can be in equilibrium in two orientations, one is stable while the other is unstable


Explanation for the correct option

Force on a Current Carrying Conductor
  1. The interaction between the magnetic field lines of a magnet and the magnetic field produced by a current-carrying conductor causes a magnetic force on the conductor (as shown in the figure) which consequently produces torque on the conductor.
  2. A current loop placed in a magnetic field experiences a torque (τ) which is expressed by the below equation.
  3. τ=M×B
  4. τ=MBsinθ, where (M) is the magnetic moment of the loop, (B) is the magnetic field density and (θ) is the angle between them.
  5. θ=00sin00=0τ=o and the current loop is said to be in a state of "stable equilibrium.
  6. θ=1800sin1800=0τ=0 and the current loop is said to be in a state of “unstable equilibrium”.
  7. The potential energy (U) of the current loop is given by the equation, U=-MBcosθ
  8. θ=1800cos1800=-1U=+ve
  9. At (θ=1800), the potential energy of the current loop is maximum due to its orientation and the current loop is in the state of “unstable equilibrium”.
  10. At (θ=1800), the torque acting on the current loop is ideally zero, however a slight push on the current loop will produce torque in the current loop.

Hence, option (C) is correct.


flag
Suggest Corrections
thumbs-up
0
BNAT
mid-banner-image