2015 · Q20
In an observation, α-particles, β-\particles and γ-rays have same energies. Their penetrating power in a given medium in increasing order will be
General KnowledgePhysics
- Aα, β, γ
- Bβ, γ, α
- Cα, γ, β
- Dβ, α, γ
Explanation
At equal energies, penetrating power is inversely related to ionising power: alpha particles are heavy and highly ionising, so they are stopped most easily; beta particles penetrate further; gamma rays, being uncharged electromagnetic radiation, penetrate the most. The increasing order of penetrating power is therefore α, β, γ — option A.