Question

An electron in an atom undergoes transition in such a way that its kinetic energy changes from $x$ to $\frac{x}{4}$, the change in potential energy will be:

• A. $+\frac{3}{2}x$
• B. $-\frac{3}{8}x$
• C. $+\frac{3}{4}x$
• D. $-\frac{3}{4}x$

Answer 1

The correct option is A $+\frac{3}{2}x$

We know that in an atom $P.E=-2K.E.$

When $K.E{.}_1=x$ so $P.E{.}_1=-2x$

and $K.E{.}_2=\frac{x}{4}$ so $P.E{.}_2=-\frac{x}{2}$

$\therefore$ Change in potential energy $=P.E_2-P.E_1$

= +$\frac{3}{2}x$