Three experiments are listedde+ g, 82jkhls.

I. Photoelectric effect

II. Davisson-Germer experiment

III. Young’s double-slit experiment

Which of the experiments show the existence of the wave behavior of matter?

  In a vacuum chamber, electromagnetic radiag,-xebg(lc kh- y-jk6tion of frequencies $f_A$​<$f_B$​ just manage to produce a non-zero photocurrent from metals A and B respectively. When illuminated by an electromagnetic radiation of frequency $f$>$f_B$​, the stopping voltage for the photocurrents from plates A and B are recorded to be $V_A$​ and $V_B$​ respectively.
Which of the following is true about $V_A$​ and $V_B$​?

  Two lasers, A and B emit light of the same wavelength. If the intensity of A is greater than that of B, which of the following statements would be the correct interpretations of this situation using the wave and particle models of light.

  The graph below shows the graph of the maximum ki-ch mp pa+-khq3blys16p 3i -qnetic energy ($E_k$​)of the emitted electrons against incident frequency ($f$) plotted by a student investigating the work function for a particular metal.

Which of the following can be used by the student to get an approximate value for the work function of the metal in question?

  Light from a sodium lamp i.m ()ou a zcmji64:pt 0mz5jjof wavelength is directed towards a metal surface and elz iu4pjjj)a5(:.mo 6c0t imm zectrons until a stopping potential of $V_s$​ is applied. The wavelength of the incident light is halved. Which of the following corresponds to the new value of the required stopping potential?

  No electrons are emitted when metal plate X is irradiated by an electromagnetxiwk5rk/i fw -f8rf7siww( n 4)ee7 5kic radiation of wavelength λ, and intensity I. Which of the following could result in emission of photoelws)wie (7rf4k5 5k8f/ixrf ie w7wk n-ectrons?

I. Decreasing the wavelength λ of incident light.

II. Increasing the intensity of electromagnetic radiation at the same wavelength.

III. Replacing metal X, with a metal of smaller threshold frequency.

  1.Light falls on a photoelectric surface with a threshold frequawf1b1 .bfdrm5 mp(6imlc; l8le ,nc3 ency of $5.2\times10^{14}\,Hz$.

State what is meant by photoelectric emission.
2.(1)Calculate the work function of the photoelectric surface in electronvolts. $ϕ$ =    $eV$
(2)The ammeter gives a reading when a violet light is used, while it reads zero when a red light with the same intensity is used. Explain this observation.
(3)The frequency of violet photons is $7.5\times10^{14}\,Hz$. Calculate the maximum speed of the emitted electrons.
3.On the axes below, sketch the variation of the photoelectric current with the potential difference for an incident frequency above the threshold frequency. Also label the stopping voltage $V_s$​. v =    $\times10^5\,ms^{-1}$

  1.A beam of electrons is izt0,g,)3 +0k,e 7 cg24bjicozeqca/ nq gqd ewncident on an iron foil (Z=56) and electrons are diffracted. In the experiment, elec2+, q4 co t70,dgezj30 /,qqw eebgznc gia)cktrons have initial kinetic energy of 42 GeV. The first diffraction minimum is observed at an angle of $49^{\circ}C$ from the average position of most of the electrons detected.

(1)Calculate the density of the iron nucleus. $ρ$ =    $\times10^{17}\,kgm^{-3}$
(2)Using the diffraction information​ given, estimate the radius $r$ of the iron nucleus . r =    $\times10^{-15}\,m$
2.In another experiment, alpha particles are emitted towards iron foil with an initial kinetic energy of $125\,ke\,V$. Estimate the distance of the closest approach to the iron nucleus of the alpha particles. r =    $\times10^{-14}\,m$

  The photocurrents produced by illuminating a metal plat,lp/s7wk4mak 2t7u ad e with yellow light beams of intensitudtmp,/l7saakk47 2 wies $I_1$​ and $I_2$​ are $i_1$​ and $i_2$​ respectively. The corresponding stopping voltages are $V_1$​ and $V_2$​. Given that $I_1$​<$I_2$​ , which of the following statements is true about the photocurrents and the stopping voltages?

  1.De Broglie related the wavelength of v w6vmnagcb l5:4n*e)a particle to its momentum. State what is mea)ve 4c*va6bg5 :wnnmlnt by matter waves.
2.(1)Show that the wavelength $λ$ of an electron of mass $m$ and kinetic energy $E$ can be found from
λ = $\frac{h}{\sqrt{2mE}}$
(2)Assuming that the magnitude of the energy of a given energy level of an atom is equal to the kinetic energy of the electron, show that the wavelength of the electron in the second energy level in a hydrogen atom is approximately $6.7\times10^{−10}\,m$. $λ$ =    $\times10^{-10}\,m$
(3)Use the wavelength from b(ii) to estimate the orbital radius of this electron. r =    $\times10^{-10}\,m$

  RRed and blue light beams of equal intensities illuminam- lfqbnjv.g( ty522bte a photosensitive plate and pro5 b.qv n22tg(lbm y-fjduce photocurrents $I_R$​ and $I_B$​ respectively. The respective stopping voltages against the two photocurrents are $V_R$​ and $V_B$​.
Consider the following statements:
I. $I_R$​>$I_B$​
II. $V_R$​<$V_B$​
III. Photoelectrons with higher kinetic energy result in a higher current.
Which statements are correct?

  In a laboratory experimenwl ;rd(.+qxri f7fs lc5 oyn7 d2t.,hct, $n$ moles of photons of wavelength $λ$ are normally incident every second per square meter on a solar sail. Which of the following expressions correctly states the photo-pressure on the solar sail, given that the photons are reflected elastically.

  Two photosensitive plate 5(9-dfco skdt f6t j3(e.pxm,u d3lrys A and B with threshold frequencies $f_A$​ and $f_B$​ are illuminated in a vacuum with an electromagnetic radiation of wavelength λ such that photoelectrons are emitted from both plates. The corresponding stopping voltages are recorded to be $V_A$​ and $V_B$​ respectively.
The ratio $\frac{V_B-V_A}{f_A​-f_B}$