Question

The de-Broglie wavelength of an electron accelerated through a potential difference of 100 V is:

• A. 12.27
• B. 1.227
• C. 0.1227
• D. 122.7

Hint:

Higher accelerating voltage results in a shorter de-Broglie wavelength.

Answer 1

The Correct Option is B

Step 1: Concept
The shortcut formula for an electron's de-Broglie wavelength is $\lambda = \frac{12.27}{\sqrt{V}}$ .
Step 2: Analysis
Given $V = 100 \text{ V}$.
$\lambda = \frac{12.27}{\sqrt{100}} = \frac{12.27}{10}$.
Step 3: Conclusion
$\lambda = 1.227$ .
Final Answer: (B)