Question

At a place the value of horizontal component of the earth's magnetic field H is $3\times {10}^{-5}Weber/m^2$ . A metallic rod AB of length 2 m placed in east-west direction, having the end A towards east, falls vertically downward with a constant velocity of 50 m/s. Which end of the rod becomes positively charged and what is the value of induced potential difference between the two ends

• A. End A, $3\times {10}^{-3}mV$
• B. End A, 3 mV
• C. End B, $3\times {10}^{-3}mV$
• D. End B, 3 mV

Answer 1

The correct option is B End A, 3 mV

Induced potential difference between two ends $=Blv=B_{H}lv$
$=3\times {10}^{-5}\times 2\times 50=30\times {10}^{-3}volt=3$ milli volt
By Fleming's right hand rule, end A becomes positively charged.