A bar magnet is hung by a thin cotton thread in a uniform horizontal magnetic field and is in equilibrium state. The energy required to rotate it by 60o is W. Now the torque required to keep the magnet in this new position is
A
$${W \over {\sqrt 3 }}$$
B
$$\sqrt 3 W$$
C
$${{\sqrt 3 W} \over 2}$$
D
$${{2W} \over {\sqrt 3 }}$$
2
NEET 2016 Phase 1
MCQ (Single Correct Answer)
+4
-1
The magnetic susceptibility is negative for
A
ferromagnetic material only
B
paramagnetic and ferromagnetic materials
C
diamagnetic material only
D
paramagnetic material only
3
AIPMT 2015
MCQ (Single Correct Answer)
+4
-1
A rectangular coil of length 0.12 m and width 0.1 m having 50 turns of wire is suspended vertically in a uniform magnetic field of strength 0.2 weber/m2. The coil carries a current of 2 A. If the plane of the coil is inclined at an angle of 30o with the direction of the field, the torque required to keep the coil in stable equilibrium will be
A
0.24 Nm
B
0.12 Nm
C
0.15 Nm
D
0.20 Nm
4
AIPMT 2014
MCQ (Single Correct Answer)
+4
-1
Following figures show the arrangement of bar magnets in different configurations. Each magnet has magnetic dipole moment $$\overrightarrow m .$$ Which configuration has highest net magnetic dipole moment ?
