Question

The de-Broglie wavelength of a 10 KeV electron is equal to:

• A. \( 12.3 \text{Å} \)
• B. \( 1.23 \text{Å} \)
• C. \( 0.123 \text{Å} \)
• D. \( 123 \text{Å} \)

Answer 1

The Correct Option is B

The de-Broglie wavelength is given by: \[ \lambda = \frac{h}{\sqrt{2mE}} \] For a 10 KeV electron, using standard values for \( h \) and \( m \), we get: \[ \lambda \approx 1.23 \text{Å} \]