Question

Doubly ionised helium atom and hydrogen ions are accelerated, from rest, through the same potential difference. The ratio of final velocities of helium and hydrogen is(a) 1 : 2(b) 2 : 1(c) 1 : 2(d) 2 : 1

Answer 1

Answer:

Explanation:

Ionised atoms = Helium (Given)

Ionised ions = Hydrogen (Given)

Potential difference = constant (Given)

Thus,

mv² = eV, or

V = (2eV/m)1/2

The mass of helium ion is four times than that of hydrogen ion.

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

vHe/vH = √2

Thus, The ratio of final velocities of helium and hydrogen is √2:1