Passive absorption of minerals depends on which of the following?

The intercepts on the $x$-axis made by the tangents to the curve $y = \int_0^x |t| dt, x \in R$ which are parallel to the line $y = 2x$ are equal to:

In the Davisson and Germer experiment,the velocity of electrons emitted from the electron gun can be increased by

The wavelength of the first line in the Balmer series in the hydrogen spectrum is $\lambda$. What is the wavelength of the second line?

$A$ projectile is projected with velocity $k v_e$ in the vertically upward direction from the ground into space. ($v_e$ is the escape velocity and $k < 1$). If air resistance is considered to be negligible,then the maximum height from the centre of the Earth to which it can go will be: ($R =$ radius of Earth)

In the Compton scattering process,the incident $X$-radiation is scattered at an angle of $60^{\circ}$. The wavelength of the scattered radiation is $0.22 \ \mathring{A}$. The wavelength of the incident $X$-radiation in $\mathring{A}$ units is: