The correct option is B v=1.55×106 m/s;λ=4.7×10−10 m
1.5 times of 13.6 eV, i.e., 20.4 eV, is absorbed by the hydrogen atom out of which 6.8 eV (20.4 - 13.6) is convereted to kinetic energy. KE=6.8 eV=6.8×(1.602×10−19coulomb)×(1volt)=1.09×10−18 J
Now, KE=12mv2
or v=√2KEm=
⎷2(1.09×10−18 J(9.1×10−31 kg)=1.55×106 m/s.
From De Broglie equation we have :
λ=hmv=(6.63×10−34J.s)(9.1×10−31 kg)(1.55×106 m/s)
=4.70×10−10 m