Question

Assertion : A deuteron and an a-particle are placed in an electric field. If $F_1$ and $F_2$ be the forces acting on them and $a_1$ and $a_2$ be their accelerations respectively then, $a_1 = a_2$.
Reason : Forces will be same in electric field.

• A. If both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
• B. If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
• C. If Assertion is correct but Reason is incorrect.
• D. If both the Assertion and Reason are incorrect.

Answer 1

Answer: (C)

$q _{ d }= e , m _{ d }=2 m _{ p }=2 m$
$q _{\alpha}=2 e , m _{\alpha}=4 m _{ p }=4 m$
$F _{1}= F _{\alpha}= eE , F _{2}= F _{\alpha}=2 e E \neq F _{1}$
Further, $a _{1}=\frac{ F _{1}}{2 m }=\frac{ eE }{2 m }$
anda $_{2}=\frac{ F _{2}}{2 m }=\frac{2 e E }{4 m }=\frac{ eE }{2 m }= a _{1}$