question_answer

The circuit in figure consists of wires at the top and bottom and identical springs as the left and right sides. The wire at the bottom has a mass of 10 g and is 5 cm long. The wire is hanging as shown in the figure. The springs stretch 0.5 cm under the weight of the wire and the circuit has a, total resistance of \[12\Omega .\] When the lower wire is subjected to a static magnetic field, the springs, stretch an additional 0.3 cm. The magnetic field is                                             [JEE ONLINE 12-05-2012]

A) 0.6 T and directed out of page

B) 1.2 T and directed into the plane of page

C) 0.6 T and directed into the plane of page

D) 1.2 T and directed out of page