List of top Physics Questions on Dual nature of radiation and matter

A light wave described by E = 60[\(\sin(3 \times 10^{15})t + \sin(12 \times 10^{15})t\)] (in SI units) falls on a metal surface of work function 2.8 eV. The maximum kinetic energy of ejected photoelectron is (approximately)________ eV. (h=\(6.6 \times 10^{-34}\) J.s. and e=\(1.6 \times 10^{-19}\) C)
What are de Broglie waves? Show that the wavelength of the electromagnetic radiation is equal to the de Broglie wavelength of its quantum (photon).
The energy of an electron revolving in the nth orbit in Bohr model of hydrogen atom is proportional to:
The momentum of a photon associated with a microwave of wavelength 4.00 cm is:
Find the ratio of de-Broglie wavelengths of deuteron having energy E and \(\alpha\)-particle having energy 2E :
Whether the total mass of nuclei increases, decreases or remains unchanged?
Does the process require energy or produce energy?
Atomic spectral emission lines of hydrogen atom are incident on a zinc surface. The lines which can emit photoelectrons from the surface are members of:
The momentum (in kg·m/s) of a photon of frequency \( 6.0 \times 10^{14} \) Hz is:
A laser beam of frequency \( 3.0 \times 10^{14} \) Hz produces average power of 9 mW. Find (i) the energy of a photon of the beam, and (ii) the number of photons emitted per second on an average by the source.
A photon and an electron (mass \(m\)) have the same energy \(E\). The ratio \( \frac{\lambda_{\text{photon}}}{\lambda_{\text{electron}}} \) of their de Broglie wavelengths is: (\(c\) is the speed of light)
Radiations of two frequencies are incident on a metal surface of work function 2.0 eV one by one. The energies of their photons are 2.5 eV and 4.5 eV respectively. Find the ratio of the maximum speed of the electrons emitted in the two cases.

When a photon of suitable frequency is incident on a metal surface, a photoelectron is emitted from it. If the frequency is below a threshold frequency (ν0) for the surface, no photoelectron is emitted. For a photon of frequency ν (ν > ν0), the kinetic energy of the emitted photoelectron is: 
Km = h(ν − ν0)
The photocurrent can be stopped by applying a potential V0, called the "stopping potential," on the anode. Thus, the maximum kinetic energy of photoelectrons is: 
Km = eV0 = h(ν − ν0)
The experimental graph between V0 and ν for a metal is shown in the figure. This is a straight line of slope m.
experimental graph between V0 and ν

Two spherical black bodies radiate the same amount of heat per second. If their temperatures are \( T_1 \) and \( T_2 \), and their radii are \( R_1 \) and \( R_2 \), respectively, find the relation between their temperatures and radii.
The de Broglie wavelength associated with an electron accelerated through a potential difference of 2400 V is nearly
If the de Broglie wavelength of a proton accelerated through a potential difference $V_1$ is same as the de Broglie wavelength of an alpha particle accelerated through $V_2$, then $V_1 : V_2 = $
20 kV electrons can produce X-rays with a minimum wavelength of
State Einstein's photoelectric equation and mention physical significance of each term involved in it. The wavelength of incident light is 4000Å. Calculate the energy of incident photon.
An electron in hydrogen atom stays in its second orbit for \(10^{-8}\) s. How many revolutions will it make around the nucleus in that time? [ Given : \(e = 1.6 \times 10^{-19}\) C, \(m = 9.1 \times 10^{-31}\) kg ]
An electron, a proton, an \(\alpha\)-particle and a hydrogen atom are moving with the same kinetic energy. The associated de-Broglie wavelength will be longest for --
A laser produces a beam of light of frequency $5 \times 10^{14}$ Hz with an output power of 33 mW. The average number of photons emitted by the laser per second is (Planck's constant = $6.6 \times 10^{-34}$ Js)
Which of the following phenomena does not explain by wave nature of light.
(A) reflection
(B) diffraction
(C) photoelectric effect
(D) interference
(E) polarization
Choose the most appropriate answer from the options given below :
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): Number of photons increases with increase in frequency of light.
Reason (R): Maximum kinetic energy of emitted electrons increases with the frequency of incident radiation.
In the light of the above statements, choose the most appropriate answer from the options given below:
An electron and an alpha particle are accelerated by the same potential difference. Let λe and λα denote the de-Broglie wavelengths of the electron and the alpha particle, respectively, then:
An electron and a proton have the same wavelength λ. This implies they have the same: