COMEDK Exam 2019 Solved Paper

Given, potential difference, V=45.5V
Velocity, v= ?
Energy acquired by the electron after getting accelerated through the potential difference V is eV, which is equal to its kinetic energy.
Hence, kinetic energy (KE)=‌

1

2

mev2=eV
‌‌ [where, ‌me=‌ mass of electron] ‌
‌⇒‌‌v=√‌

2eV

me

‌
Substituting the given values, we get
⇒‌‌v‌=√‌

2×1.6×10−19×45.4

9.11×10−31

‌=√16×1012=4×106ms−1