Question

Consider figure. Suppose the voltage applied to A is increased. The diffracted beam will have the maximum at a value of $\theta$ that

Davisson - Germer electron diffraction arrangement

• A. Will be larger than the earlier value
• B. Will be the same as the earlier value
• C. Will be less than the earlier value
• D. Will depend on the target

Answer 1

Answer: (D)

Will depend on the target

Answer 2

: Velocity acquired by a particle while falling from a height H is

$v = \sqrt { 2 g H }$ ……. (i)

As $\lambda = \frac { h } { m v } = \frac { h } { m \sqrt { 2 g H } }$ (using (i))

Or $\lambda \propto \frac { 1 } { \sqrt { H } }$