A narrow beam of alpha particles with kinetic energy `1.0 MeV` falls normally on a platinum foil
Channel: Doubtnut
Date: 23/08/2020

A narrow beam of alpha particles with kinetic energy `1.0 MeV` falls normally on a platinum foil `1.0 mu` thick. The scattered particles are observed at an angle of `60^(@)` to the incident beam direction by means of a counter with a circular inlet area `1.0 cm^(2)` located at the distacne `10 cm`from the scattering section of the foil. What fraction of scattered alpha particles reaches the counter inlet?