Question

Two parallel rails of a railway track insulated from each other and with the ground are connected to a millivoltmeter. The distance between the rails is one metre. A train is traveling with a velocity of 72 kmph along the track. The reading of the millivoltmeter (in m V) is : (Vertical component of the earth's magnetic induction is $2\times 10^{-5}T$ )

• A. 144
• B. 0.72
• C. 0.4
• D. 0.2

Answer 1

Answer: (C)

0.4

Answer 2

$e = B_{\nu} l u = 2 \times 10^{-5} \times 1 \times 20 = 0.4 mV$