Question

If the kinetic energy of a free electron doubles, its de-Broglie wavelength changes by the factor-

• A. 1/$\sqrt{2}$
• B. $\sqrt{2}$
• C. ½
• D. 2

Answer 1

Answer: (A)

1/$\sqrt{2}$

Answer 2

l =$\frac{h}{\sqrt{2mE}}$

l¢ =$\frac{h}{\sqrt{2 \times m \times 2E}}$

l¢ =$\frac{\lambda}{\sqrt{2}}$