Two insulating plates are both uniformly charged in such a way that the potential difference between them is $V_2-V_1=20 \mathrm{~V}$. (i.e. plate 2 is at a higher potential). The plates are separated by $d=0.1 \mathrm{~m}$ and can be treated as infinitely large. An electron is released from rest on the inner surface of plate 1 . What is its speed when it hits plate $2 ?$ $\left(\mathrm{e}=1.6 \times 10^{-19} \mathrm{C}, \mathrm{m}_{\mathrm{e}}=9.11 \times 10^{-31} \mathrm{~kg}\right)$

• A

  $32 \times 10^{-19} \mathrm{~m} / \mathrm{s}$
• Correct answer
  B

  $2.65 \times 10^6 \mathrm{~m} / \mathrm{s}$
• C

  $7.02 \times 10^{12} \mathrm{~m} / \mathrm{s}$
• D

  $1.87 \times 10^6 \mathrm{~m} / \mathrm{s}$

Hence, the correct answer is option: 'B'.