Question icon
Grade upto college level Modern Physics

Doubly ionised helium atoms and hydrogen ions are accelerated from rest through the same potential drop. The ratio of the final velocities of the helium and the hydrogen ion is

(a) 1/2

(b) 2

(c) 1/sqrt2

(d) sqrt2

Profile image of Amit Saxena
12 Years agoGrade upto college level
Answers icon

1 Answer

Profile image of Amit Saxena
12 Years ago

 (d)

 mv2 = eV, or, V = (2eV/m)1/2

the mass of helium ion is four times that of hydrogen ion.

Further, the charge on helium ion is twice that of hydrogen ion.

    vHe/vH =   sqrt 2