31 Year NEET Previous Year Questions: Dual Nature of Radiation & Matter - 1 - NEET MCQ

According to Einstein’s photoelectric equation, the graph between the kinetic energy of photoelectrons ejected and the frequency of
incident radiation is [2004]

A photosensitive metallic surface has workfunction, hv₀. If photons of energy 2 hv₀ fallon this surface, the electrons come out with amaximum velocity of 4 ×10⁶ m/s. When thephoton energy is increased to 5 hv₀, thenmaximum velocity of photoelectrons will be

[2005]

The work functions for metals A, B and C arerespectively 1.92 eV, 2.0 eV and 5 eV.According to Einstein s equation, the metalswhich will emit photoelectrons for a radiationof wavelength 4100 Å is/are [2005]

When photons of energy hv fall on an aluminiumplate (of work function E₀), photoelectrons ofmaximum kinetic energy K are ejected. If thefrequency of the radiation is doubled, themaximum kinetic energy of the ejectedphotoelectrons will be     [2006]

In a discharge tube ionization of enclosed gas isproduced due to collisions between [2006]

A photo-cell employs photoelectric effect toconvert      [2006]

The momentum of a photon of energy 1 MeV inkg m/s, will be [2006]

Monochromatic light of frequency 6.0 × 10¹⁴ Hzis produced by a laser. The power emitted is 2 × 10^–3 ω. The number of photons emitted, onthe average, by the sources per second is            [2007]

A 5 watt source emits monochromatic light ofwavelength 5000 Å. When placed 0.5 m away, itliberates photoelectrons from a photosensitivemetallic surface. When the source is moved to adistance of 1.0 m, the number of photoelectronsliberated will be reduced by a factor of [2007]

The work function of a surface of aphotosensitive material is 6.2 eV. The wavelengthof incident radiation for which the stoppingpotential is 5 V lies in the: [2008]

In the phenomenon of electric discharge throughgases at low pressure, the coloured glow in thetube appears as a result of: [2008]

A particle of mass 1 mg has the same wavelengthas an electron moving with a velocity of 3×10⁶ ms^–1. The velocity of the particle is:    [2008]
(mass of electron = 9.1×10^–31 kg)

The number of photo electrons emitted for lightof a frequency v (higher than the threshold frequency v₀) is proportional to: [2009]

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? [2009]

Monochromatic light of wavelength 667 nm isproduced by a helium neon laser. The poweremitted is 9 mW. The number of photons arrivingper sec on the average at a target irradiated bythis beam is: [2009]

A beam of cathode rays is subjected to crossed Electric (E) and Magnetic fields (B). The fields are adjusted such that the beam is not deflected. The specific charge of the cathode rays is given by: [2010]

A source S1 is producing, 10¹⁵ photons persecond of wavelength 5000 Å. Another source S₂ is producing 1.02×10¹⁵ photons per secondof wavelength 5100Å Then, (power of S₂)/(power of S₁) is equal to : [2010]

The potential difference that must be applied tostop the fastest photoelectrons emitted by anickel surface, having work function 5.01 eV,when ultraviolet light of 200 nm falls on it, mustbe:  [2010]

Photoelectric emmision occurs only whenthe incident light has more than a certainminimum [2011]

In the Davisson and Germer experiment, thevelocity of electrons emitted from the electrongun can be increased by [2011]

Light of two different frequencies whosephotons have energies 1 eV and 2.5 eVrespectively illuminate a metallic surface whosework function is 0.5 eV successively. Ratioof maximum speeds of emitted electrons will be[2011]

Electrons used in an electron microscope areaccelerated by a voltage of 25 kV. If the voltageis increased to 100kV then the de–Brogliewavelength associated with the electrons would

In photoelectric emission process from a metalof work function 1.8 eV, the kinetic energy ofmost energetic electrons is 0.5 eV. Thecorresponding stopping potential is     [2011]

The threshold frequency for a photosensitivemetal is 3.3 × 10¹⁴ Hz. If light of frequency 8.2 × 10¹⁴ Hz is incident on this metal, the cut-offvoltage for the photoelectric emission is nearly   [2011M]

A 200 W sodium street lamp emits yellow lightof wavelength 0.6 μm. Assuming it to be 25%  efficient in converting electrical energy to light,the number of photons of yellow light it emitsper second is [2012]

Monochromatic radiation emitted when electronon hydrogen atom jumps from first excited tothe ground state irradiates a photosensitivematerial. The stopping potential is measured tobe 3.57 V. The threshold frequency of the materialsis : [2012]

If the momentum of electron is changed by P,then the de Broglie wavelength associated withit changes by 0.5%. The initial momentum ofelectron will be : [2012M]