question_answer

The two rails of a railway track, insulated from each other and the ground, are connected to a milli voltmeter. What is the reading of the milli voltmeter when a train travels at a speed of 180 km/hour along the track, given that the vertical component of earth's magnetic field is\[0.2\times {{10}^{-4}}\,weber/{{m}^{2}}\] and the rails are separated by 1 m?

A) 1

B) 3    

C) 5

D) 7