Photoelectric effect experiments are performed using three different metal plates $p, q$ and $r$ having work functions $\phi_p=2.0 \ eV, \phi_q=2.5 \ eV$ and $\phi_r=3.0 \ eV$,respectively. $A$ light beam containing wavelengths of $550 \ nm, 450 \ nm$ and $350 \ nm$ with equal intensities illuminates each of the plates. The correct $I-V$ graph for the experiment is:

The radiation corresponding to the $3 \rightarrow 2$ transition of a hydrogen atom falls on a gold surface to generate photoelectrons. These electrons are passed through a magnetic field of $5 \times 10^{-4} \, T$. Assume that the radius of the largest circular path followed by these electrons is $7 \, mm$. The work function of the metal is $..... \, eV$. (Mass of electron $= 9.1 \times 10^{-31} \, kg$)

In the Thomson spectrograph experiment,four positive ions $P, Q, R,$ and $S$ are situated on the $Y-X$ curves as shown in the figure.

Match List-$I$ (Fundamental Experiment) with List-$II$ (its conclusion) and select the correct option from the choices given below the list.

List-$I$	List-$II$
$a$. Franck-Hertz Experiment	$i$. Particle nature of light
$b$. Photo-electric Experiment	$ii$. Discrete energy levels of atom
$c$. Davisson-Germer Experiment	$iii$. Wave nature of electron
	$iv$. Structure of atom

The dual nature of radiation is demonstrated by:

Assertion $(A)$: In the photoelectric effect,on increasing the intensity of light,both the number of electrons emitted and the kinetic energy of each of them increase,but the photoelectric current remains unchanged.
Reason $(R)$: The photoelectric current depends only on the wavelength of light.