Answer:
The speed is [tex]\sqrt{2}v_{0}[/tex].
(a) is correct option.
Explanation:
Given that,
Potential difference [tex]V= V_{0}[/tex]
Speed [tex]v = v_{o}[/tex]
If it were accelerated instead
Potential difference [tex]V'=2V_{0}[/tex]
We need to calculate the speed
Using formula of initial work done on proton
[tex]W = q V[/tex]
We know that,
[tex]\Delta W=\Delta K.E[/tex]
[tex]q V=\dfrac{1}{2}mv^2[/tex]
Put the value into the formula
[tex]q V_{0}=\dfrac{1}{2}mv_{0}^2[/tex]
[tex]v_{0}^2=\dfrac{2qV_{0}}{m}[/tex]....(I)
If it were accelerated instead through a potential difference of [tex]2 V_{0}[/tex], then it would gain a speed will be given as :
Using an above formula,
[tex]v_{0}'^2=\dfrac{2qV_{0}}{m}[/tex]
Put the value of [tex]V_{0}[/tex]
[tex]v_{0}'^2=\dfrac{2q\times2V_{0}}{m}[/tex]
[tex]v_{0}'=\sqrt{\dfrac{4qV_{0}}{m}}[/tex]
[tex]v_{0}'=\sqrt{2}v_{0}[/tex]
Hence, The speed is [tex]\sqrt{2}v_{0}[/tex].