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Dual Nature of Radiation and Matter · Question 6

NEET (UG) 2025MCQEasy📈 Topic in 25% papers+4−1
1

Which of the following options represent the variation of photoelectric current with property of light shown on the x-axis? [figure]

  1. A and D
  2. B and D
  3. A only
  4. A and C

Answer

(3) A only

Solution

As per NCERT, for a frequency above the threshold frequency, the photoelectric current is directly proportional to the intensity of incident light (number of photons per second).

Current versus intensity is a straight line through the origin: graph A is correct.

Graph B shows a current that does not change with intensity: wrong.

As per NCERT, the saturation photoelectric current is independent of the frequency of incident radiation (for a given intensity and > 0).

Graphs C and D, in which the current rises linearly with frequency, are wrong (graph D is the shape of the stopping potential or maximum kinetic energy versus frequency graph).

Only A is correct.

Answer: (3)

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2

A photon and an electron (mass m) have the same energy E. The ratio ( photon/ electron) of their de Broglie wavelengths is: (c is the speed of light)

  1. c 2mE
  2. 1c E/2m
  3. E/2m
  4. c 2mE
NEET (UG) 2025
3

The graph which shows the variation of ( 1 2 ) and its kinetic energy, E is (where is de Broglie wavelength of a free particle):

  1. [figure]
  2. [figure]
  3. [figure]
  4. [figure]
NEET (UG) 2024
4

If c is the velocity of light in free space, the correct statements about photon among the following are: Choose the correct answer from the options given below:

  1. A and B only
  2. A, B, C and D only
  3. A, C and D only
  4. A, B, D and E only
NEET (UG) 2024
5

An electron and an alpha particle are accelerated by the same potential difference. Let e and denote the de-Broglie wavelengths of the electron and the alpha particle, respectively, then:

  1. e >
  2. e = 4
  3. e =
  4. e <
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6

If is the work function of photosensitive material in eV and light of wavelength of numerical value = hce metre, is incident on it with energy above its threshold value at an instant then the maximum kinetic energy of the photo-electron ejected by it at that instant (Take h-Planck's constant, c-velocity of light in free space) is (in SI units):

  1. e + 2
  2. 2e -
  3. e - e
  4. e +
RE-NEET (UG) 2024
7

The work functions of Caesium (Cs), potassium (K) and sodium (Na) are 2.14 eV, 2.30 eV and 2.75 eV respectively. If incident electromagnetic radiation has an incident energy of 2.20 eV, which of these photosensitive surfaces may emit photoelectrons?

  1. Both Na and K
  2. K only
  3. Na only
  4. Cs only
NEET (UG) 2023
8

The minimum wavelength of X-rays produced by an electron accelerated through a potential difference of V volts is proportional to :

  1. 1V
  2. 1 V
  3. V2
  4. V
NEET (UG) 2023
9

When two monochromatic lights of frequency, and 2 are incident on a photoelectric metal, their stopping potential becomes Vs2 and Vs respectively. The threshold frequency for this metal is

  1. 2
  2. 3
  3. 23
  4. 32
NEET (UG) 2022
10

The graph which shows the variation of the de Broglie wavelength ( ) of a particle and its associated momentum (p) is

  1. [figure]
  2. [figure]
  3. [figure]
  4. [figure]
Out of syllabusNEET (UG) 2022
11

The light rays having photons of energy 4.2 eV are falling on a metal surface having a work function of 2.2 eV. The stopping potential of the surface is

  1. 6.4 V
  2. 2 eV
  3. 2 V
  4. 1.1 V
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