Question

The frequency order is for $\gamma$ - rays $(b),X$ - rays $(a)$ UV - rays $(c),$ then

• A. $b>a>c$
• B. $a>b>c$
• C. $c>b>c$
• D. $a>c>b$

Answer 1

Answer: (A)

$\gamma$ - rays are most penetrative. They are the fallout of nuclear reaction. $X-$ rays are used for $X-$ raying the human body is rest to $\gamma$ in penetrating. $UV$ rays cannot penetrate the human body but are harmful to the skin. Penetrative power $\propto$ frequency
Thus $U_{\text{gamma }}>U_{X\text{ -ray }}>U_{UV}$ or $b>a>c$