Question

An electron is projected into an electric field of intensity $9\times {10}^{6}N{C}^{-1}$ in the direction of the field acting towards east. Its acceleration is (neglect gravity)

• A. $1.6\times {10}^{18}m{s}^{-2}$ towards west
• B. $1.6\times {10}^{18}m{s}^{-2}$towards east
• C. $9\times {10}^{18}m{s}^{-2}$ towards west
• D. $9\times {10}^{18}m{s}^{-2}$towards east

Answer 1

Answer: (A)

$1.6\times {10}^{18}m{s}^{-2}$ towards west

Fonce on $e^{-}$ will in opposites direction of E as $F=Eq$
$\therefore F=-Ee$
$a=\frac{-Ee}{m}$

$=\frac{-9\times {10}^6\times 1.6\times {10}^{-19}}{4.1\times {10}^{-31}}$

$a=-1.6\times {10}^{18}m/s^2$

$a=1.6\times {10}^{18}m/s^2$ towards west