AIPMT-PRELIMS Physics Dual Nature of Matter & Radiation Class 12 Questions

An α-particle moves in a circular path of radius 0.83 cm in the presence of a magnetic field of 0.25 Wb/m². The de Broglie wavelength associated with the particle will be

Monochromatic radiation emitted when electron on hydrogen atom jumps from first excited to the ground state irradiates a photosensitive material. The stopping potential is measured to be 3.57 V. The threshold frequency of the material is

The decreasing order of wavelength of infrared, microwave, ultraviolet and gamma rays is

In photoelectric emission process from a metal of work function 1.8 eV, the kinetic energy of most energetic electrons is 0.5 eV. The corresponding stopping potential is

Electrons used in an electron microscope are accelerated by a voltage of 25 kV. If the voltage is increased to 100 kV then the de-Broglie wavelength associated with the electrons would

Light of two different frequencies whose photons have energies 1 eV and 2.5 eV respectively illuminate a metallic surface whose work function is 0.5 eV successively. Ratio of maximum speeds of emitted electrons will be

The potential difference necessary to stop the fastest photo electrons emitted by a nickel surface, having work function 5.01 eV, when ultraviolet light of 200 nₘ falls on it, must be

The number of photo electrons emitted for light of a frequency ν (higher than the threshold frequency ν₀) is proportional to:

The Figure shows a plot of photo current versus anode potential for a photo sensitive surface for three different radiations. Which one of the following is a correct statement?

A particle of mass 1 mg has the same wavelength as an electron moving with a velocity of 3 × 10⁶ ms⁻¹. The velocity of the particle is : (mass of electron = 9.1 × 10⁻³¹ kg)

The work function of a surface of a photosensitive material is 6.2 eV. The wavelength of the incident radiation for which the stopping potential is 5 V lies in the :

Monochromatic light of frequency 6.0 × 10¹⁴ Hz is produced by a laser. The power emitted is 2 × 10⁻³ W. The number of photons emitted, on the average, by the sources per second is

A 5 watt source emits monochromatic light of wavelength 5000 Å. When placed 0.5 m away, it liberates photoelectrons from a photosensitive metallic surface. When the source is moved to a distance of 1.0 m, the number of photoelectrons liberated will be reduced by a factor of

A photo-cell employs photoelectric effect to convert:

In a discharge tube ionization of enclosed gas is produced due to collisions between :

When photons of energy hν fall on an aluminium plate (of work function E₀), photoelectrons of maximum kinetic energy K are ejected. If the frequency of the radiation is doubled, the maximum kinetic energy of the ejected photoelectrons will be :

The momentum of a photon of energy 1 MeV in kg m/s, will be:

The work functions for metals A, B and C are respectively 1.92 eV, 2.0 eV and 5 eV. According to Einstein's equation, the metals which will emit photoelectrons for a radiation of wavelength 4100 Å is/are:

A photosensitive metallic surface has work function, hν₀. If photons of energy 2hν₀ fall on this surface, the electrons come out with a maximum velocity of 4 × 10⁶ m/s. When the photon energy is increased to 5hν₀, then maximum velocity of photoelectrons will be:

According to Einstein's photoelectric equation, the graph between the kinetic energy of photoelectrons ejected and the frequency of incident radiation is :-

A photoelectric cell is illuminated by a point source of light 1 m away. When the source is shifted to 2m then -

The value of plank's constant is :-

When ultraviolet rays incident on metal plate then photoelectric effect does not occur, it occurs by incidence of :-

Which of the following is not the property of cathode rays :-

A photo-cell is illuminated by a source of light, which is placed at a distance d from the cell. If the distance become d/2, then number of electrons emitted per second will be:

By photo electric effect, Einstein proved :

For given energy, corresponding wavelength will be E = 3.03 × 10⁻¹⁹ Joules (h = 6.6 × 10⁻³⁴ J x sec., C = 3 × 10⁸ m/sec.)