The spectrum obtained from an electric lamp or a red-hot heater is:

Some laws/processes are given in Column $I$. Match these with the physical phenomena given in Column $II$.

Column $I$	Column $II$
$(A)$ Transition between two atomic energy levels	$(p)$ Characteristic $X$-rays
$(B)$ Electron emission from a material	$(q)$ Photoelectric effect
$(C)$ Mosley's law	$(r)$ Hydrogen spectrum
$(D)$ Change of photon energy into kinetic energy of electrons	$(s)$ $\beta$-decay

When a light source of power $P$ emitting monochromatic light of wavelength $\lambda$ is kept at a distance $r$ from a photosensitive surface of work function $\phi$ and surface area $A$,which of the following is the wrong option?

The anode voltage of a photocell is kept constant. The wavelength of the light incident on the cathode is changed gradually. Which of the following graphs represents the variation of the photoelectric current $(I)$ with the wavelength $(\lambda)$?

Which of the following support the quantum nature of the $EM$ radiations?
$(A)$ Photoelectric effect
$(B)$ Compton effect
$(C)$ Doppler effect
$(D)$ Field effect

The anode voltage of a photocell is kept fixed. The wavelength $\lambda$ of the light falling on the cathode is gradually changed. The plate current $I$ of the photocell varies as follows: