Dual Nature of Radiation
Practice Questions
MCQ (Single Correct Answer)
1
If we consider an electron and a photon of same de-Broglie wavelength, then they will have same
KCET 2025
2

The anode voltage of a photocell is kept fixed. The frequency of the light falling on the cathode is gradually increased. Then the correct graph which shows the variation of photo current I with the frequency $v$ of incident light is

KCET 2025
3

Light of energy $E$ falls normally on a metal of work function $\frac{E}{3}$. The kinetic energies $K$ of the photo electrons are

KCET 2024
4

The photoelectric work function for photo metal is 2.4 eV . Among the four wavelengths, the wavelength of light for which photoemission does not take place is

KCET 2024
5

A 60 W source emits monochromatic light of wavelength 662.5 nm. The number of photons emitted per second is

KCET 2023
6

In an experiment to study photoelectric effect the observed variation of stopping potential with frequency of incident radiation is as shown in the figure. The slope and $$y$$-intercept are respectively

KCET 2023 Physics - Dual Nature of Radiation Question 23 English

KCET 2023
7

The energy gap of an LED is $$2.4 \mathrm{~eV}$$. When the LED is switched ON, the momentum of the emitted photons is

KCET 2023
8

The kinetic energy of the photoelectrons increases by $$0.52 \mathrm{~eV}$$ when the wavelength of incident light is changed from $$500 \mathrm{~nm}$$ to another wavelength which is approximately

KCET 2022
9

The de-Broglie wavelength of a particle of kinetic energy $$K$$ is $$\lambda$$, the wavelength of the particle, if its kinetic energy $$\frac{K}{4}$$ is

KCET 2022
10

In a photo electric experiment, if both the intensity and frequency of the incident light are doubled, then the saturation photoelectric current

KCET 2022
11

The work-function of a metal is 1 eV. Light of wavelength $$3000 \mathop A\limits^o$$ is incident on this metal surface. The velocity of emitted photoelectrons will be

KCET 2021
12

A proton moving with a momentum $$p_1$$ has a kinetic energy $$1 / 8$$th of its rest mass-energy. Another light photon having energy equal to the kinetic energy of the possesses a momentum $$p_2$$. Then, the ratio $$\frac{p_1-p_2}{p_1}$$ is equal to

KCET 2021
13

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

KCET 2021
14

A hot filament liberates an electron with zero initial velocity. The anode potential is $$1200 \mathrm{~V}$$. The speed of the electron when it strikes the anode is

KCET 2020
15

The de-Broglie wavelength associated with electron of hydrogen atom in this ground state is

KCET 2020
16

The following graph represents the variation of photocurrent with anode potential for a metal surface. Here $$I_1, I_2$$ and $$I_3$$ represents intensities and $$\gamma_1, \gamma_2, \gamma_3$$ represent frequency for curves $$1,2$$ and $$3$$ respectively, then

KCET 2020 Physics - Dual Nature of Radiation Question 12 English

KCET 2020
17

An electron is moving with an initial velocity $$\mathbf{v}=v_0 \hat{\mathbf{i}}$$ and is in a uniform magnetic field $$\mathbf{B}=B_0 \hat{\mathbf{j}}$$. Then its de-Broglie wavelength

KCET 2019
18

Light of certain frequency and intensity incident on a photosensitive material causes photoelectric effect. If both the frequency and intensity are doubled, the photoelectric saturation current becomes

KCET 2019
19
The number of photons falling per second on a completely darkened plate to produce a force of $6.62 \times 10^{-5} \mathrm{~N}$ is $n$. If the wavelength of the light falling is $5 \times 10^{-7} \mathrm{~m}$, then $n=$ $\ldots \ldots \ldots \times 10^{22}$. (Take, $h=6.62 \times 10^{-34} \mathrm{~J}-\mathrm{s}$ )
KCET 2018
20
The maximum kinetic energy of emitted photoelectrons depends on
KCET 2018
21
A proton and an $\alpha$-particle are accelerated through the same potential difference $V$. The ratio of their de-Broglie wavelength is
KCET 2018
22
From the following graph of photo current against collector plate potential, for two different intensities of light $I_1$ and $I_2$, one can conclude KCET 2017 Physics - Dual Nature of Radiation Question 3 English
KCET 2017
23
A particle is dropped from a height $H$. The de-Broglie wavelength of the particle depends on height as
KCET 2017