Q1 / 160 · AP EAMCET 2024 (20 May Shift 2) · Chemistry
If uncertainty in position and momentum of an electron are equal, then uncertainty in its velocity is
- Correct answerA$\frac{1}{2 m} \sqrt{\frac{h}{\pi}}$
- B$\frac{1}{m} \sqrt{\frac{h}{\pi}}$
- C$\sqrt{\frac{h}{\pi}}$
- D$m \sqrt{\frac{h}{\pi}}$
Solution
$\begin{aligned} & \Delta \mathrm{x} \times \Delta \mathrm{p}=\frac{\mathrm{h}}{4 \pi} \\ & \text { Given, } \Delta \mathrm{x} \times \Delta \mathrm{p} \\ & (\Delta \mathrm{p})^2=\frac{\mathrm{h}}{4 \pi} \Rightarrow \Delta \mathrm{p}=\sqrt{\frac{\mathrm{h}}{4 \pi}} \\ & \Rightarrow \mathrm{~m} \Delta \mathrm{v}=\frac{1}{2} \sqrt{\frac{\mathrm{~h}}{\pi}} \\ & \Rightarrow \Delta \mathrm{v}=\frac{1}{2 \mathrm{~m}} \sqrt{\frac{\mathrm{~m}}{\pi}}\end{aligned}$
Hence, the correct answer is option: 'A'.