2. Sample Papers
  3. NEET

NEET Sample Paper NEET Sample Test Paper-80

  • question_answer
    A short bar magnet of magnetic moment \[0.5 J\,T{{\,}^{-}}^{1}\] is placed in a uniform magnetic filed of 0.4 T. The magnet is in stable equilibrium when potential energy is

    A)  0.2 J               

    B)  - 0.2 J

    C)  zero                             

    D)  None of these

    Correct Answer: B

    Solution :

    Given, magnetic moment, \[\operatorname{M}\,\,= 0.5 J{{T}^{-}}^{1}\] magnetic field, \[\operatorname{B} = 0.4 T\] Now, potential energy \[\operatorname{U}=\,\,-\overline{M}\,\cdot \overline{B}\,\,=\,\,-MB\,\,cos\,\theta \] For stable equilibrium, \[\theta =0{}^\circ \] \[\therefore \,\,\,\,\,\operatorname{U}= -MB=- \left( 0.5 \right) \times  \left( 0.4 \right)\,\,=\,\,- 0.2 J\]


You need to login to perform this action.
You will be redirected in 3 sec spinner