The Davisson-Germer experiment that first demonstrated the wave nature of matter used electrons accelerated to $54 \ V$. Determine the wavelength of the electrons in the Davisson-Germer experiment in $\mathring{A}$.

$A$ clock pendulum made of invar has a period of $0.5 \, s$ at $20^{\circ} C$. If the clock is used in a climate where the temperature averages to $30^{\circ} C$, how much time does the clock lose in each oscillation? (For invar, $\alpha = 9 \times 10^{-7} /{ }^{\circ} C$, $g = \text{constant}$)

The number of ways of arranging $8$ men and $4$ women around a circular table such that no two women can sit together is

What are the oxidation numbers of nitrogen in $NH_4NO_3$?

Identify the incorrect statement among the following:

The locus of a point such that the sum of its distances from the points $(0, 2)$ and $(0, -2)$ is $6$,is