Question 1 :
The energy $E$ and the momentum $p$ of a photon is given by $E = hv$ and $p = \displaystyle\ \frac{h}{\lambda}$. The velocity of photon will be 
Question 2 :
An electron (mass $m$) with initial velocity $\vec { v } ={ v }_{ 0 }\hat { i } +{ v }_{ 0 }\hat { j } $ is an electric field $\vec { E } =-{ E }_{ 0 }\hat { k } $. If ${ \lambda }_{ 0 }$ is initial de-Broglie wave length at time $t$ is given by
Question 3 :
A beam of light is strikes on a piece of metal whose work function is 6.0 eV. Calculate the maximum kinetic energy of photoelectrons ejected from the metals surface if frequency of light is $7.2\times 10^{15}Hz$.
Question 5 :
A monochromatic source of light operating at 200 W emits $4 \times 10^{20}$ photons/second. Then the wavelength of light used is<br/>
Question 6 :
When photons of energy $h\nu$ are incident on the surface of photosensitive material of work function$\displaystyle h\nu_{0},$ then
Question 7 :
If the ionization energy for the hydrogen atom is $13eV$, the energy required to excite it from the ground state to the next higher state is nearly
Question 8 :
The wavelengths of a proton and a photon are same. Then :<br/>
Question 9 :
Light of wavelength $200\, nm$ shines on an aluminium, $4.20 eV$ is required to eject an electron. What is the kinetic energy of the fastest ejected electrons?
Question 10 :
The de Broglie wavelength of a thermal neutron at $927^oC$ is $\lambda$. Its wavelength at $327^oC$ will be<br>
Question 11 :
The de-Broglie wavelength of a neutron at $27^oC$ is $\lambda$. What will be its wavelength at $927^oC$
Question 12 :
A particle having a de Broglie wavelength of 1.0 $A^{0}$ is associated with a momentum of (given $h = 6.6 \times 10^{-34}$ Js)<br/>
Question 14 :
Two radiations of photons energies $1eV$ and $2.5eV$ successively illuminate a photosensitive metallic surface of work function $0.5eV$. The ratio of the maximum speeds of the emitted electrons is-
Question 15 :
Fora certain metal, incident frequency $\upsilon$ is five times of thresholdfrequency $\upsilon$ and the maximum velocity of coming out photoelectrons is $8\, \times\,10^6m s^{-1}$ If $\upsilon \, = \, 2\upsilon_o$, the maximum velocity ofphotoelectrons will be
Question 16 :
Radiation of wavelength $\lambda$, is incident on a photocell. The fastest emitted electron has speed $v$. If the wavelength is charged to $\cfrac { 3\lambda }{ 4 } $, the speed of the fastest emitted electron will be:
Question 17 :
If the energy of incident photon and work function of metal are E eV and$\displaystyle \phi _{0} eV$ respectively, then the maximum velocity of emitted photoelectron will be
Question 18 :
A particle of mass $4m$ at rest decays into two particles of masses $m$ and $3m$ having non-zero velocities. The ratio of the de Broglie wavelengths of the particles 1 and 2 is:
Question 19 :
If a photon and an electron have same de-broglie wavelength, then
Question 20 :
The threshold wavelength of lithium is$\displaystyle 8000\mathring {A}.$ When light of wavelength$\displaystyle 9000\mathring {A}$ is made incident on it, then the photoelectrons
Question 22 :
A free particle with initial kinetic energy E and de-broglie wavelength $\lambda$ enters a region in which ithas potential energy U. What is the particle's new de-Broglie wavelength?
Question 24 :
When photons of wavelength $\displaystyle \lambda _{1}$ are incident on an isolated sphere suspended by an insulated thread the corresponding stopping potential is found to be $\displaystyle \Delta v$ When photons of wavelenght $\displaystyle \lambda _{2}$ are used, the corresponding stopping potential was thrice of the above value if light of wavelength $\displaystyle \lambda _{3}$ is sued the stoppong potential for this case would be 
Question 25 :
If the kinetic energy of a free electron doubles, its de Broglie wavelength changes by the factor
Question 26 :
In hydrogen spectrum, the wavelength of the line is 656 nm, where as in the spectrum of a distant galaxy, the line wavelength is 706 nm. Estimated speed of galaxy with respect to the earth is :<br>
Question 27 :
When photons of energy $4.25\ eV$ strike the surface of metal A, the ejected photoelectrons have maximum kinetic energy, $T_A$ $eV$ and deBroglie wavelength $\lambda_A$. The maximum kinetic energy of photoelectrons liberated from another metal $B$ by photons of energy $4.70 eV$ is $ T_B$=${(T_A-1.50)eV}$. If the de Broglie wavelength of these photoelectrons is $\lambda_B=2\lambda_A$, then
Question 28 :
A 60 W bulb is placed at a distance of 4m from you. The bulb is emitting light of wavelength 600 nm uniformly in all directions. In 0.1 s, how many photons enter your eye if the pupil of the eye is having a diameter of 2 mm? [Take $hc=1240 eV-nm]$<br>
Question 29 :
A pulse of light of duration 100 ns is absorbed completely by a small object initially at rest. Power of the pulse is 30$mW$and the speed of light is $3\times 10^{8}m/s$. The final momentum of the object is:<br/>
Question 30 :
The circumference of the second Bohr orbit of electron in hydrogen atom is $600nm$. The potential difference that must be applied between the plates so that the electrons have the de Broglie wavelength corresponding in this circumference is
Question 31 :
If the shortest wavelength of the continuous X-ray spectrum coming out of a Coolidge tube is $0.01nm$, then the de Broglie wavelength of the electron reaching the target metal in the Coolidge tube is approximately<br/>$ (hc = 12400 e VA, h = 6.63 \times 10^{-34} $ in  MKS, mass  of  electron$  = 9.1 \times 10^{-31}kg)$<br/>
Question 32 :
The work functions of tungsten and sodium are $5.06\ eV $ and $2.53\ eV $ respectively.If threshold wavelength of sodium is $5896 \mathring{A} $ , then the threshold wavelength of tungsten will be
Question 33 :
The wave nature of particles was studied using diffraction of particle beams by crystal lattices. The wavelength of the waves associated with fast moving particles was found to be in agreement with the de Broglie relation.<br/>For a particle of mass $m$ moving with kinetic energy $E$, the de Broglie wavelength is<br/>
Question 34 :
The wavelength of the de-Broglie wave associated with a thermal neutron of mass $m$ at absolute temperature $T$ is given by: ($k$ is the Boltzmann constant)<br/>
Question 35 :
De-Broglie wavelength of an electron accelerated by a voltage of 50 V is close to: $(|e|=1.6 \times 10^{-19} C, m_e=9.1 \times 10^{-31}kg, h=6.6 \times 10^{-34} Js).$ 
Question 36 :
Representing the stopping potential V along y-axis and $(1/\lambda)$ along x-axis for a given photocathode, the curve is a straight line, the slope of which is equal to<br>
Question 37 :
A particle moving with kinetic energy E has de Broglie wavelength $\lambda$. If energy $\Delta E$ is added to its energy, the wavelength become $\lambda /2$. Value of $\Delta E$, is?
Question 38 :
What is the ratio of wavelength of a photon and that of an electron of mass, m of the sameenergy $E$?<br>
Question 39 :
An electron (of mass m) and a photon have the same energy E in the range of a few eV. The ratio of the de-Broglie wavelength associated with the electron and the wavelength of the photon is (c = speed of light in vacuum)
Question 40 :
A $100$ watt bulb emits monochromatic light of wavelength $400$ nm. Calculate the number of photons emitted per second by bulb :
