At some location on earth, the horizontal component of earth's magnetic field is 18 × 10-6 T. At this location, magnetic needle of length 0.12 m and pole strength 1.8 A-m is suspended from its mid-point using a thread, it makes 45° angle with horizontal in equilibrium. To keep this needle horizontal, the vertical force that should be applied at one of its ends is

At some location on earth, the horizontal component of earth's magneti

1.	At some location on earth, the horizontal component of earth's magnetic field is 18 × 10-6 T. At this location, magnetic needle of length 0.12 m and pole strength 1.8 A-m is suspended from its mid-point using a thread, it makes 45° angle with horizontal in equilibrium. To keep this needle horizontal, the vertical force that should be applied at one of its ends is
A.	6.5 × 10-5 N
B.	3.6 × 10-5 N
C.	1.3 × 10-5 N
D.	1.8 × 10-5 N
Answer» B. 3.6 × 10-5 N