Dual Nature of Radiation and Matter - Result Question 63
67. Kinetic energy of an electron, which is accelerated in a potential difference of $100 V$ is
[1995]
(a) $1.6 \times 10^{-17} J$
(b) $1.6 \times 10^{-19} J$
(c) $1.6 \times 10^{-21} J$
(d) $1.6 \times 10^{-25} J$
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Answer:
Correct Answer: 67. (a)
Solution:
- (a) Potential difference $(V)=100 V$. The kinetic energy of an electron $=1 eV=1 \times(1.6 \times 10^{-19})$ $=1.6 \times 10^{-19} J$. Therefore kinetic energy in 100 volts $=(1.6 \times 10^{-19}) \times 100=1.6 \times 10^{-17} J$. K.E. $=qV$
$=1.6 \times 10^{-19} \times 100 J=1.6 \times 10^{-17}$