Three experiments are listbbx1da.xd2c*0wepjm4+wl s z k) ;wo:ed.

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 radiation of tl;n-n ;xvs8h 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 thewv 2bg:ywg ;wy)06cvea qr( 6v graph of the maximum kinetic 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 of wavelength is directed towards arwawhn 968zt)kxf i/, metal surface and electrons until a stopping pow at96rw )8zxki/,fnhtential 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 electromagneticff rg:w gu,4(im if+3pj*dlp8 radiation of wavelength λ, and intensity I. Which of the follow 8 +3j:gfirfpf,wg(u*pi4l md ing could result in emission of photoelectrons?

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 sf/;z yi 0mmvo e- vs6d3a(77k l4z iz8givxaw/urface with a threshold frequency 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 inci yvd;) r afhve:l67u4ldent on an iron foil (Z=56) and electrons are diffracted. In the experiment, electrons have initial kinetic energy: v;46hd7al le)uvfr y 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 w6ml4twl(qa .metal plate with yellow light beams of intensiwt6qm.l(w4 al ties $I_1$​ 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 wanphq 353wq4t*n dx +arvelength of a particle to its momentum. State what is meantwa +rq*x 4nq533dp nht 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 inten*q :cr f44 yjmrlf y*2ppl+2jnsities illuminate a photosensitive plate and p4*fp rj:+lm2f*j q4 yyrnpl2croduce 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 experiment,ih xz2b*n,b8e2 9ft fn $n$ 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 plates A and B with t ytqu/6h9i6 )s2to kanhreshold 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 $\frac{V_B-V_A}{f_A​-f_B}$