Question

Two element A and B with atomic numbers $Z_A$ and $Z_B$ are used to produce characteristic X-rays with frequencies $v_A$ and $v_B$ respectively. If $Z_A:Z_B=1:2$, then $v_A:v_B$ will be

• A. $1:\sqrt{2}$
• B. $1:8$
• C. $4:1$
• D. $1:4$

Answer 1

Answer: (D)

$1:4$

Given that, $Z_A:Z_B=1:2$
We know that, $v\propto Z^2$
Hence,
$\Rightarrow \frac{v_A}{v_B}=\frac{(1{)}^2}{(2{)}^2}$
$\Rightarrow v_A:v_B=1:4$