Identify the incorrect relationship - Vidyadip

MCQ

Identify the incorrect relationship

A
Number of waves in an orbit, $n=\frac{2 \pi r}{\lambda}$
B
Number of revolutions of an electron per second in $n^{ m }$ orbit $=\frac{v_n}{2 \pi r_n}$
C
Wavelength of an electron $=\frac{h}{p}$
✓
Speed of a (de-Broglie wavelength) particle accelerated by a potential difference $V$ is $v=\frac{2 e V}{m}$

✓

Answer

Correct option: D.

Speed of a (de-Broglie wavelength) particle accelerated by a potential difference $V$ is $v=\frac{2 e V}{m}$

d
(d)

Kinetic energy gained by an electron accelerated by potential $V$ is

$K E=e V$

or $\frac{1}{2} m v^2=e V$

$v=\sqrt{\frac{2 e V}{m}}$

Hence $(d)$ is wrong.

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