An electron beam is moving between two parallel plates having ele… - Vidyadip

MCQ

An electron beam is moving between two parallel plates having electric field $1.125 \times 10^{-6} \mathrm{~N} / \mathrm{m}$. A magnetic field $3 \times 10^{-10} \mathrm{~T}$ is also applied so that beam of electrons do not deflect. The velocity of the electron is

A
$4225 \mathrm{~m} / \mathrm{s}$
✓
$3750 \mathrm{~m} / \mathrm{s}$
C
$2750 \mathrm{~m} / \mathrm{s}$
D
$3200 \mathrm{~m} / \mathrm{s}$

✓

Answer

Correct option: B.

$3750 \mathrm{~m} / \mathrm{s}$

$v=\frac{E}{B}=\frac{1.125 \times 10^{-6}}{3 \times 10^{-10}}=3750 \mathrm{~m} / \mathrm{s}$

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