Home › Bihar Board Class 12 (Science) › Physics › Magnetism and Matter › The potential energy of a magnetic dipole in a f…
The potential energy of a magnetic dipole in a field is taken as zero when the angle between m and B is
A0 degrees
B45 degrees
C180 degrees
D90 degrees
Answer & Solution
Correct answer: D. 90 degrees
With U = -mB cos(theta) and the constant set to zero, U vanishes at 90 degrees, when the needle is perpendicular to the field.
Related questions
Why is the phrase magnetic lines of force avoided for field lines?An iron nail near a bar magnet feels a net attraction becauseTwo identical iron bars repel at some pair of ends. This shows thatFor a diamagnetic material in an external field, the magnetisation M isThe magnetic intensity H has the same unit as which quantity?A dipole of moment 3 A m^2 is turned from the stable to the unstable position in a 0.2 T fTwo magnetic field lines never cross because at the crossing pointA magnetised needle in a uniform field feels torque but no net force because