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 travelling with a velocity of $72 \mathrm{~km} / \mathrm{h}$ along the track. The reading of the millivoltmeter (in…

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 travelling with a velocity of $72 \mathrm{~km} / \mathrm{h}$ along the track. The reading of the millivoltmeter (in $\mathrm{mV}$ ) is (vertical component of the earth's magnetic induction is $2 	imes 10^{-5} \mathrm{~T}$ )

Aicharya · Accepted Answer

Induced emf, $e=B v l$ where, $\begin{aligned} v & =	ext { velocity of train } \ & =72 	imes \frac{5}{18} \ & =20 \mathrm{~m} / \mathrm{s} \ & =2 	imes 10^{-5} 	imes 20 	imes 1 \ & =2 	imes 10^{-5} 	imes 20 \ & =40 	imes 10^{-5} \mathrm{v} \ & =40 	imes 10^{-2} \mathrm{mV} \ & =0.4 \mathrm{mV} \end{aligned}$

Two parallel rails of a railway track insulated from each other and with the ground are connected to a…

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