In photo electric effect

$A.$ The photocurrent is proportional to the intensity of the incident radiation.

$B.$ Maximum Kinetic energy with which photoelectrons are emitted depends on the intensity of incident light.

$C.$ Max. $K.E$ with which photoelectrons are emitted depends on the frequency of incident light.

$D.$ The emission of photoelectrons require a minimum threshold intensity of incident radiation.

$E.$ Max. K.E of the photoelectrons is independent of the frequency of the incident light.

Choose the correct answer from the options given below:

A  radiation of energy $'E'$ falls normally on a perfectly reflecting surface. The momentum transferred to the surface is $( C =$ Velocity of light $)$

If a photon has velocity $c$ and frequency $\nu$, then which of following represents its wavelength

The force on a hemisphere of radius $1\, cm$ if a parallel beam of monochromatic light of wavelength $500\, nm$. falls on it with an intensity of $0.5\, W/cm^2$, striking the curved surface in a direction which is perpendicular to the flat face of the hemisphere is (assume the collisions to be perfectly inelastic)

In photoelectric effect, the K.E. of electrons emitted from the metal surface depends upon

Using the Heisenberg uncertainty principle, arrange the following particles in the order of increasing lowest energy possible.

$(I)$ An electron in $H _{2}$ molecule

$(II)$ A hydrogen atom in a $H _{2}$ molecule

$(III)$ A proton in the carbon nucleus

$(IV)$ $A H _{2}$ molecule within a nanotube