Dual Nature of Radiation · Physics · AP EAPCET

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MCQ (Single Correct Answer)

1

When photons of energy $8 \times 10^{-19} \mathrm{~J}$ incident on a photosensitive material, the de-Broglie wavelength of the photoelectrons emitted with maximum kinetic energy is $10 $ Å. The work function of the photosensitive material is nearly

AP EAPCET 2025 - 26th May Morning Shift
2

The minimum wavelength of X-rays produced by 20 kV electrons is nearly

AP EAPCET 2025 - 26th May Morning Shift
3

The de-Broglie wavelength associated with an electron accelerated through a potential difference of $\frac{200}{3} \mathrm{~V}$ is nearly

AP EAPCET 2025 - 27th May Morning Shift
4

The ratio of de-Broglie wavelengths associated with thermal neutrons at temperatures $127^{\circ} \mathrm{C}$ and $352^{\circ} \mathrm{C}$ is

AP EAPCET 2025 - 26th May Evening Shift
5

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 $=6.6 \times 10^{-34} \mathrm{Js}$ )

AP EAPCET 2025 - 24th May Morning Shift
6
If the de-Broglie wavelength of an electron is 2 nm , then its kinetic energy is nearly (Planck's constant $=6.6 \times 10^{-34} \mathrm{Js}$ and mass of electron $=9 \times 10^{-31} \mathrm{~kg}$ )
AP EAPCET 2025 - 23rd May Evening Shift
7
If a proton and an alpha particle are accelerated through the same potential difference, then the ratio of their de-Broglie wavelengths is
AP EAPCET 2025 - 23rd May Morning Shift
8

If the threshold wavelength of light for photoelectric emission to take place from a metal surface is $6250 \mathop {\rm{A}}\limits^{\rm{o}}$, then the work function of the metal is (Planck's constant $=6.6 \times 10^{-34} \mathrm{Js}$ )

AP EAPCET 2025 - 22nd May Evening Shift
9

A camera is fabricated using a semiconducting material having a band gap of 3 eV . The wavelength of light if can detect is nearly

AP EAPCET 2025 - 22nd May Morning Shift
10

If the linear momentum of a proton is changed by $p_0$ then the de-Broglie wavelength associated with the proton changes by $0.25 \%$. Then the initial linear momentum of the proton is

AP EAPCET 2025 - 21st May Morning Shift
11

If an electron in the excited state falls to ground state, a photon of energy 5 eV is emitted, then the wavelength of the photon is nearly

AP EAPCET 2025 - 21st May Morning Shift
12
A photon incident on a metal of work function 2 eV produced photoelectron of maximum kinetic energy of 2 eV . The wavelength associated with the photon is
AP EAPCET 2024 - 23th May Morning Shift
13

Light of wavelength $4000\mathop {\rm{A}}\limits^{\rm{o}}$ is incident on a sodium surface for which the threshold wavelength of photoelectrons is $5420 \mathop {\rm{A}}\limits^{\rm{o}}$. The work function of sodium is

AP EAPCET 2024 - 22th May Evening Shift
14

The surface of a metal is first illuminated with a light of wavelength 300 nm and later illuminated by another light of wavelength 500 nm . It is observed that the ratio of maximum velocities of photoelectrons in two cases is 3 . The work function of metal value is close to

AP EAPCET 2024 - 22th May Morning Shift
15
The maximum wavelength of light which causes photoelectric emission from photosensitive metal surface is $\lambda_0$. Two light beams of wavelengths $\frac{\lambda_0}{3}$ and $\frac{\lambda_0}{9}$ incident on the metal surface. The ratio of the maximum velocities of the emitted photoelectrons is
AP EAPCET 2024 - 21th May Evening Shift
16
A blue lamp emits light of mean wavelength $4500$ Å. The lamp is rated at 150 W and $8 \%$ efficiency. Then, the number of photons are emitted by the lamp per second
AP EAPCET 2024 - 21th May Morning Shift
17
If the kinetic energy of a particle in motion is decreased by $36 \%$, the increase in de-Broglie wavelength of the particle is
AP EAPCET 2024 - 20th May Evening Shift
18
An electron of mass $m$ with initial velocity $\mathbf{v}=v_0 \hat{\mathbf{i}}\left(v_0>0\right)$ enters in an electric field $\mathbf{E}=-E_0 \hat{\mathbf{i}}$ ( $E_0$ is constant $>0$ ) at $t=0$. If $\lambda$ is its de-Broglie wavelength initially, then the de-Broglie wavelength after time $t$ is
AP EAPCET 2024 - 20th May Morning Shift
19
The longest wavelength of light that can initiate photo electric effect in the metal of work function 9 eV is
AP EAPCET 2024 - 19th May Evening Shift
20
Energy required to remove an electron from aluminium surface is 4.2 eV . If light of wavelength $2000 \mathring{A}$ falls on the surface, the velocity of the fastest ejected electron the surface will be
AP EAPCET 2024 - 18th May Morning Shift
21

The following statement is correct in the case of photoelectric effect

AP EAPCET 2022 - 5th July Morning Shift
22

In a photoelectric experiment light of wavelength 800 nm produces photoelectrons with the smallest de-Broglie wavelength of 1 nm . Light of 400 nm produces photoelectrons with smallest de-Broglie wavelength of 0.5 nm. Then the work function of the metal used in the experiment is nearly.

AP EAPCET 2022 - 4th July Evening Shift
23

The metal which has the highest work function in the following is

AP EAPCET 2022 - 4th July Morning Shift
24

If a photocell is illuminated with a radiation of 1240 $$\mathop A\limits^o $$, the stopping potential is found to be 8V. Then, the work-function of the emitter and the threshold wavelength are

AP EAPCET 2021 - 20th August Evening Shift
25

The graph between the maximum speed $$(v_{max})$$ of a photoelectron and frequency $$(\nu)$$ of the incident radiation, in photoelectric effect is correctly represented by

AP EAPCET 2021 - 20th August Morning Shift
26

The de-Broglie wavelength associated with a proton under the influence of an electric potential of 100 V is

AP EAPCET 2021 - 19th August Evening Shift
27

Radiation of wavelength $$300 \mathrm{~nm}$$ and intensity $$100 \mathrm{~W}-\mathrm{m}^{-2}$$ falls on the surface of a photosensitive material. If $$2 \%$$ of the incident photons produce photoelectron, the number of photoelectrons emitted from an area of $$2 \mathrm{~cm}^2$$ of the surface is nearly

AP EAPCET 2021 - 19th August Morning Shift