## MCQ (Single Correct Answer)

Monochromatic light of frequency $6 \times 10^{14} \mathrm{~Hz}$ is produced by a laser. The power emitted is $2 \times 10^{-3} \mathrm{~W}$. How many...

Conductivity of a photodiode starts changing only if the wavelength of incident light is less than $660 \mathrm{~nm}$. The band gap of photodiode is f...

The de Broglie wavelengths of a proton and an $\alpha$ particle are $\lambda$ and $2 \lambda$ respectively. The ratio of the velocities of proton and ...

In a photoelectric effect experiment a light of frequency 1.5 times the threshold frequency is made to fall on the surface of photosensitive material....

When a metal surface is illuminated by light of wavelength $$\lambda$$, the stopping potential is $$8 \mathrm{~V}$$. When the same surface is illumina...

For the photoelectric effect, the maximum kinetic energy $$\left(E_k\right)$$ of the photoelectrons is plotted against the frequency $$(v)$$ of the in...

If the total energy transferred to a surface in time $$\mathrm{t}$$ is $$6.48 \times 10^5 \mathrm{~J}$$, then the magnitude of the total momentum deli...

The work function of a substance is $$3.0 \mathrm{~eV}$$. The longest wavelength of light that can cause the emission of photoelectrons from this subs...

Two sources of light emit with a power of $$200 \mathrm{~W}$$. The ratio of number of photons of visible light emitted by each source having wavelengt...

The de-Broglie wavelength of an electron is the same as that of a photon. If velocity of electron is $$25 \%$$ of the velocity of light, then the rati...

The threshold frequency of a metal with work function $$6.63 \mathrm{~eV}$$ is :

The de Broglie wavelength of an electron having kinetic energy $\mathrm{E}$ is $\lambda$. If the kinetic energy of electron becomes $\frac{E}{4}$, the...

Given below are two statements:
Statement I : Out of microwaves, infrared rays and ultraviolet rays, ultraviolet rays are the most effective for the e...

The difference between threshold wavelengths for two metal surfaces $$\mathrm{A}$$ and $$\mathrm{B}$$ having work function $$\phi_{A}=9 ~\mathrm{eV}$$...

A proton and an $$\alpha$$-particle are accelerated from rest by $$2 \mathrm{~V}$$ and $$4 \mathrm{~V}$$ potentials, respectively. The ratio of their ...

The ratio of the de-Broglie wavelengths of proton and electron having same Kinetic energy :
(Assume $$m_{p}=m_{e} \times 1849$$ )

A metallic surface is illuminated with radiation of wavelength $$\lambda$$, the stopping potential is $$V_{0}$$. If the same surface is illuminated wi...

The variation of stopping potential $$\left(\mathrm{V}_{0}\right)$$ as a function of the frequency $$(v)$$ of the incident light for a metal is shown ...

The de Broglie wavelength of a molecule in a gas at room temperature (300 K) is $$\lambda_1$$. If the temperature of the gas is increased to 600 K, th...

In photo electric effect
A. The photocurrent is proportional to the intensity of the incident radiation
B. Maximum Kinetic energy with which photoelec...

Proton $$(\mathrm{P})$$ and electron (e) will have same de-Broglie wavelength when the ratio of their momentum is (assume, $$\mathrm{m}_{\mathrm{p}}=1...

The work functions of Aluminium and Gold are $$4.1 ~\mathrm{eV}$$ and and $$5.1 ~\mathrm{eV}$$ respectively. The ratio of the slope of the stopping po...

The kinetic energy of an electron, $$\alpha$$-particle and a proton are given as $$4 \mathrm{~K}, 2 \mathrm{~K}$$ and $$\mathrm{K}$$ respectively. The...

The threshold frequency of a metal is $$f_{0}$$. When the light of frequency $$2 f_{0}$$ is incident on the metal plate, the maximum velocity of photo...

A proton moving with one tenth of velocity of light has a certain de Broglie wavelength of $$\lambda$$. An alpha particle having certain kinetic energ...

If the two metals $\mathrm{A}$ and $\mathrm{B}$ are exposed to radiation of wavelength $350 \mathrm{~nm}$. The work functions of metals $\mathrm{A}$ a...

Given below are two statements : One is labelled as Assertion A and the other is labelled as Reason R
Assertion A : The beam of electrons show wave na...

If a source of electromagnetic radiation having power $$15 \mathrm{~kW}$$ produces $$10^{16}$$ photons per second, the radiation belongs to a part of ...

An electron accelerated through a potential difference $V_{1}$ has a de-Broglie wavelength of $\lambda$. When the potential is changed to $V_{2}$, its...

A small object at rest, absorbs a light pulse of power $$20 \mathrm{~mW}$$ and duration $$300 \mathrm{~ns}$$. Assuming speed of light as $$3 \times 10...

The ratio of de-Broglie wavelength of an $$\alpha$$ particle and a proton accelerated from rest by the same potential is $$\frac{1}{\sqrt m}$$, the va...

The threshold wavelength for photoelectric emission from a material is 5500 $$\mathop A\limits^o $$. Photoelectrons will be emitted, when this materia...

Given below are two statements :
Statement I : Stopping potential in photoelectric effect does not depend on the power of the light source.
Statement ...

Electron beam used in an electron microscope, when accelerated by a voltage of 20 kV, has a de-Broglie wavelength of $$\lambda_0$$. IF the voltage is ...

An $$\alpha$$-particle, a proton and an electron have the same kinetic energy. Which one of the following is correct in case of their de-Broglie wavel...

From the photoelectric effect experiment, following observations are made. Identify which of these are correct.
A. The stopping potential depends only...

An $$\alpha$$ particle and a proton are accelerated from rest through the same potential difference. The ratio of linear momenta acquired by above two...

The kinetic energy of emitted electron is E when the light incident on the metal has wavelength $$\lambda$$. To double the kinetic energy, the inciden...

Two streams of photons, possessing energies equal to five and ten times the work function of metal are incident on the metal surface successively. The...

The equation $$\lambda=\frac{1.227}{x} \mathrm{~nm}$$ can be used to find the de-Brogli wavelength of an electron. In this equation $$x$$ stands for :...

With reference to the observations in photo-electric effect, identify the correct statements from below :
(A) The square of maximum velocity of photoe...

An electron (mass $$\mathrm{m}$$) with an initial velocity $$\vec{v}=v_{0} \hat{i}\left(v_{0}>0\right)$$ is moving in an electric field $$\vec{E}=-E_{...

A parallel beam of light of wavelength $$900 \mathrm{~nm}$$ and intensity $$100 \,\mathrm{Wm}^{-2}$$ is incident on a surface perpendicular to the bea...

The ratio of wavelengths of proton and deuteron accelerated by potential Vp and Vd is 1 : $$\sqrt2$$. Then the ratio of Vp to Vd will be :...

A metal exposed to light of wavelength $$800 \mathrm{~nm}$$ and and emits photoelectrons with a certain kinetic energy. The maximum kinetic energy of ...

A source of monochromatic light liberates 9 $$\times$$ 1020 photon per second with wavelength 600 nm when operated at 400 W. The number of photons emi...

The electric field at a point associated with a light wave is given by
E = 200 [sin (6 $$\times$$ 1015)t + sin (9 $$\times$$ 1015)t] Vm$$-$$1
Given : ...

Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R :
Assertion A : The photoelectric effect does no...

Let K1 and K2 be the maximum kinetic energies of photo-electrons emitted when two monochromatic beams of wavelength $$\lambda$$1 and $$\lambda$$2, res...

The de Broglie wavelengths for an electron and a photon are $$\lambda$$e and $$\lambda$$p respectively. For the same kinetic energy of electron and ph...

An $$\alpha$$ particle and a carbon 12 atom has same kinetic energy K. The ratio of their de-Broglie wavelengths $$({\lambda _\alpha }:{\lambda _{C12}...

A metal surface is illuminated by a radiation of wavelength 4500 $$\mathop A\limits^o $$. The ejected photo-electron enters a constant magnetic field ...

An electron with speed v and a photon with speed c have the same de-Broglie wavelength. If the kinetic energy and momentum of electron are Ee and pe a...

A proton, a neutron, an electron and an $$\alpha$$ particle have same energy. If $$\lambda$$p, $$\lambda$$n, $$\lambda$$e and $$\lambda$$a are the de ...

Given below are two statements :
Statement I : Davisson-Germer experiment establishes the wave nature of electrons.
Statement II : If electrons have w...

The light of two different frequencies whose photons have energies 3.8 eV and 1.4 eV respectively, illuminate a metallic surface whose work function i...

The temperature of an ideal gas in 3-dimensions is 300 K. The corresponding de-Broglie wavelength of the electron approximately at 300 K, is :[me = ma...

A free electron of 2.6 eV energy collides with a H+ ion. This results in the formation of a hydrogen atom in the first excited state and a photon is r...

Consider two separate ideal gases of electrons and protons having same number of particles. The temperature of both the gases are same. The ratio of t...

A moving proton and electron have the same de-Broglie wavelength. If K and P denote the K.E. and momentum respectively. Then choose the correct option...

A monochromatic neon lamp with wavelength of 670.5 nm illuminates a photo-sensitive material which has a stopping voltage of 0.48 V. What will be the ...

In a photoelectric experiment, increasing the intensity of incident light :

The de-Broglie wavelength of a particle having kinetic energy E is $$\lambda$$. How much extra energy must be given to this particle so that the de-Br...

In a photoelectric experiment ultraviolet light of wavelength 280 nm is used with lithium cathode having work function $$\phi$$ = 2.5 eV. If the wavel...

An electron and proton are separated by a large distance. The electron starts approaching the proton with energy 3 eV. The proton captures the electro...

An electron moving with speed v and a photon moving with speed c, have same D-Broglie wavelength. The ratio of kinetic energy of electron to that of p...

When radiation of wavelength $$\lambda$$ is incident on a metallic surface, the stopping potential of ejected photoelectrons is 4.8 V. If the same sur...

What should be the order of arrangement of de-Broglie wavelength of electron ($$\lambda$$e), an $$\alpha$$-particle ($$\lambda$$a) and proton ($$\lamb...

A particle of mass 4M at rest disintegrates into two particles of mass M and 3M respectively having non zero velocities. The ratio of de-Broglie wavel...

An electron of mass me and a proton of mass mp are accelerated through the same potential difference. The ratio of the de-Broglie wavelength associate...

An electron having de-Broglie wavelength $$\lambda$$ is incident on a target in a X-ray tube. Cut-off wavelength of emitted X-ray is :

The radiation corresponding to 3 $$\to$$ 2 transition of a hydrogen atom falls on a gold surface to generate photoelectrons. The electrons are passed ...

The speed of electrons in a scanning electron microscope is 1 $$\times$$ 107 ms-1. If the protons having the same speed are used instead of electrons,...

A particle is travelling 4 time as fast as an electron. Assuming the ratio of de-Broglie wavelength of a particle to that of electron is 2 : 1, the ma...

Two identical photocathodes receive the light of frequencies f1 and f2 respectively. If the velocities of the photo-electrons coming out are v1 and v2...

An electron of mass m and a photon have same energy E. The ratio of wavelength of electron to that of photon is : (c being the velocity of light)

The de-Broglie wavelength associated with an electron and a proton were calculated by accelerating them through same potential of 100 V. What should n...

The stopping potential in the context of photoelectric effect depends on the following property of incident electromagnetic radiation :

The recoil speed of a hydrogen atom after it emits a photon in going from n = 5 state to n = 1 state will be :

Given below are two statements : one is labeled as Assertion A and the other is labelled as Reason R.Assertion A : An electron microscope can achieve ...

An electron of mass me and a proton of mass mp = 1836 me are moving with the same speed. The ratio of their de Broglie wavelength $${{{}^\lambda elect...

The stopping potential for electrons emitted from a photosensitive surface illuminated by light of wavelength 491 nm is 0.710 V. When the incident wav...

An $$\alpha$$ particle and a proton are accelerated from rest by a potential difference of 200V. After this, their de Broglie wavelengths are $$\lambd...

An X-ray tube is operated at 1.24 million volt. The shortest wavelength of the produced photon will be :

The de-Broglie wavelength of a proton and $$\alpha$$-particle are equal. The ratio of their velocities is :

Given below are two statements : Statement I : Two photons having equal linear momenta have equal wavelengths.Statement II : If the wavelength of phot...

Assuming the nitrogen molecule is moving with r.m.s. velocity at 400 K, the de-Broglie wavelength
of nitrogen molecule is close to :
(Given : nitroge...

An electron, a doubly ionized helium ion (He++) and a proton are having the same kinetic energy.
The relation between their respective de-Broglie wave...

In a photoelectric effect experiment, the graph of stopping potential V versus reciprocal of wavelength
obtained is shown in the figure. As the intens...

Particle A of mass mA = $${m \over 2}$$ moving along the x-axis with velocity v0 collides elastically with another particle B at rest having mass mB =...

Given figure shows few data points in a phot electric effect experiment for a certain metal. The
minimum energy for ejection of electron from its surf...

Two sources of light emit X-rays of wavelength 1 nm and visible light of wavelength 500 nm, respectively. Both the sources emit light of the same powe...

When the wavelength of radiation falling on a metal is changed from 500 nm to 200 nm, the
maximum kinetic energy of the photoelectrons becomes three t...

A particle is moving 5 times as fast as an
electron. The ratio of the de-Broglie wavelength
of the particle to that of the electron is 1.878 $$ \times...

An electron of mass m and magnitude of charge
|e| initially at rest gets accelerated by a constant
electric field E. The rate of change of de-Broglie
...

A particle moving with kinetic energy E has
de Broglie wavelength $$\lambda $$. If energy $$\Delta $$E is added
to its energy, the wavelength become $...

Radiation, with wavelength 6561 $$\mathop A\limits^o $$ falls on a
metal surface to produce photoelectrons. The
electrons are made to enter a uniform ...

An electron (mass m) with initial velocity $$\overrightarrow v = {v_0}\widehat i + {v_0}\widehat j$$ is in an electric field $$\overrightarrow E = ...

When photon of energy 4.0 eV strikes the
surface of a metal A, the ejected photoelectrons
have maximum kinetic energy TA eV end
de-Broglie wavelength ...

An electron (of mass m) and a photon have the same energy E in the range of a few eV. The ratio
of the de-Broglie wavelength associated with the elect...

The stopping potential V0 (in volt) as a function of frequency ($$\upsilon $$) for a sodium emitter, is shown in the figure.
The work function of sodi...

A 2 mW laser operates at wavelength of 500 nm. The number of photons that will be emitted per second is :
[Given Planck's constant h = 6.6 × 10–34 Js,...

In a photoelectric effect experiment the
threshold wavelength of the light is 380 nm. If
the wavelentgh of incident light is 260 nm, the
maximum kinet...

A particle 'P' is formed due to a completely
inelastic collision of particles 'x' and 'y' having
de-Broglie wavelengths '$$\lambda $$x' and '$$\lambda...

The electric field of light wave is given as
$$$\overrightarrow E = {10^{ - 3}}\cos \left( {{{2\pi x} \over {5 \times {{10}^{ - 7}}}} - 2\pi \times ...

A nucleus A, with a finite de-broglie
wavelength $$\lambda $$A, undergoes spontaneous fission
into two nuclei B and C of equal mass. B flies
in the sa...

Two particles move at right angle to each other.
Their de-Broglie wavelengths are $$\lambda _1$$ and $$\lambda _2$$
respectively. The particles suffer...

In a Frank-Hertz experiment, an electron of energy 5.6 eV passes through mercury vapour and emerges with an energy 0.7 eV. The minimum wavelength of p...

When a certain photosensitive surface is illuminated with monochromatic light of frequency v, the stopping
potential for the current is –V0/2. When th...

A particle A of mass 'm' and charge 'q' is accelerated by a potential difference of 50 V. Another particle B of mass ' 4 m' and charge 'q' is accelera...

In a photoelectric experiment, the wavelength of the light incident on a metal is changed from 300 nm to 400 nm. The decrease in the stopping potentia...

If the de Broglie wavelength of an electron is equal to the 10–3 times the wavelength of a photon of frequency 6 $$ \times $$ 1014 Hz, then the spee...

A metal plate of area 1 $$ \times $$ 10–4 m2 is illuminated by a radiation of intensity 16 mW/m2. The work function of the metal is 5 eV. The energy o...

In an electron microscope, the resolution that can be achieved is of the order of the wavelength of electrons used. To resolve a width of 7.5 × 10–12 ...

The magnetic field associated with a light wave is given, at the origin, by B = B0 [sin(3.14 $$ \times $$ 107)ct + sin(6.28 $$ \times $$ 107)ct]. If t...

Surface of certain metal is first illuminated with light of wavelength $$\lambda $$1 = 350 nm and then, by light of wavelength $$\lambda $$2 = 540 nm....

The de-Broglie wavelength ($$\lambda $$B) associated with the electron orbiting in the second excited state of hydrogen atom is related to that in the...

Both the nucleus and the atom of some element arein their respective first excited states. They get de-excted by emitting photons of wavelengths $$\la...

If the de Broglie wavelengths associated with a proton and an $$\alpha $$-particle are equal, then the ratio of velocities of the proton and the $$\al...

Two electrons are moving with non-relativistic speed perpendicular to each other. If corresponding de Broglie wavelength are $${\lambda _1}$$ and $${\...

A Laser light of wavelength 660 nm is used to weld Retina detachment. If a Laser pulse of width 60 ms and power 0.5 kW is used the approximate number ...

The maximum velocity of the photoelectrons emitted from the surface is v when light of frequency n falls on a metal surface. If the incident frequency...

An electron beam is accelerated by a potential difference V to hit a metallic target to produce X–rays. It
produces continuous as well as characterist...

A particle A of mass m and initial velocity v collides with a particle B of mass m/2 which is at rest. The
collision is head on, and elastic. The rati...

A photoelectric surface is illuminated successively by monochromatic light of wavelengths $$\lambda $$ and $${\lambda \over 2}.$$ If the maximum kine...

When photons of wavelength $${\lambda _1}$$ are incident on an isolated sphere, the corresponding stopping potential is found to be V. When photons of...

Radiation of wavelength $$\lambda ,$$ is incident on a photocell. The fastest emitted electron has speed $$v.$$ If the wavelength is changed to $${{3\...

Match List - $${\rm I}$$ (Fundamental Experiment) with List - $${\rm II}$$ (its conclusion) and select the correct option from the choices given below...

The anode voltage of a photocell is kept fixed. The wavelength $$\lambda $$ of the light falling on the cathode is gradually changed. The plate curren...

This question has Statement 1 and Statement 2. Of the four choices given after the statements, choose the one that best describes the two statements.
...

This question has Statement - $$1$$ and Statement - $$2$$. Of the four choices given after the statements, choose the one that best describes the two ...

Statement - $$1$$ : When ultraviolet light is incident on a photocell, its stopping potential is $${V_0}$$ and the maximum kinetic energy of the pho...

If a source of power $$4kW$$ produces $${10^{20}}$$ photons/second, the radiation belongs to a part of the spectrum called

The surface of a metal is illuminated with the light of $$400$$ $$nm.$$ The kinetic energy of the ejected photoelectrons was found to be $$1.68$$ $$eV...

In an experiment, electrons are made to pass through a narrow slit of width $$'d'$$ comparable to their de Broglie wavelength. They are detected on a ...

Wave property of electrons implies that they will show diffraction effects. Davisson and Germer demonstrated this by diffracting electrons from crysta...

Wave property of electrons implies that they will show diffraction effects. Davisson and Germer demonstrated this by diffracting electrons from crysta...

Photon of frequency $$v$$ has a momentum associated with it. If $$c$$ is the velocity of light, the momentum is

The threshold frequency for a metallic surface corresponds to an energy of $$6.2$$ $$eV$$ and the stopping potential for a radiation incident on this ...

The time taken by a photoelectron to come out after the photon strikes is approximately

The anode voltage of a photocell is kept fixed. The wavelength $$\lambda $$ of the light falling on the cathode is gradually changed. The plate curren...

If the kinetic energy of a free electron doubles, it's deBroglie wavelength changes by the factor

A photocell is illuminated by a small bright source placed $$1$$ $$m$$ away. When the same source of light is placed $${1 \over 2}$$ $$m$$ away, the n...

The work function of a substance is $$4.0$$ $$eV.$$ The longest wavelength of light that can cause photo-electron emission from this substance is app...

According to Einstein's photoelectric equation, the plot of the kinetic energy of the emitted photo electrons from a metal $$Vs$$ the frequency, of th...

Two identical photo-cathodes receive light of frequencies $${f_1}$$ and $${f_2}$$. If the velocities of the photo electrons (of mass $$m$$ ) coming ou...

Sodium and copper have work functions $$2.3$$ $$eV$$ and $$4.5$$ $$eV$$ respectively. Then the ratio of the wavelengths is nearest to

Formation of covalent bonds in compounds exhibits

## Numerical

An atom absorbs a photon of wavelength $$500 \mathrm{~nm}$$ and emits another photon of wavelength $$600 \mathrm{~nm}$$. The net energy absorbed by th...

A monochromatic light is incident on a hydrogen sample in ground state. Hydrogen atoms absorb a fraction of light and subsequently emit radiation of s...

The stopping potential for photoelectrons emitted from a surface illuminated by light of wavelength 6630 $$\mathop A\limits^o $$ is 0.42 V. If the thr...

When light of frequency twice the threshold frequency is incident on the metal plate, the maximum velocity of emitted electron is v1. When the frequen...

A particle of mass 9.1 $$\times$$ 10$$-$$31 kg travels in a medium with a speed of 106 m/s and a photon of a radiation of linear momentum 10$$-$$27 kg...

A light beam of wavelength 500 nm is incident on a metal having work function of 1.25 eV, placed in a magnetic field of intensity B. The electrons emi...

A certain metallic surface is illuminated by monochromatic radiation of wavelength $$\lambda$$. The stopping potential for photoelectric current for t...

Two stream of photons, possessing energies equal to twice and ten times the work function of metal are incident on the metal surface successively. The...

The surface of a metal is illuminated alternately
with photons of energies E1 = 4 eV and E2 = 2.5 eV
respectively. The ratio of maximum speeds of the
...

A beam of electrons of energy E scatters from
a target having atomic spacing of 1 $$\mathop A\limits^o $$. The first
maximum intensity occurs at $$\th...

When radiation of wavelength $$\lambda $$ is used to
illuminate a metallic surface, the stopping
potential is V. When the same surface is
illuminated ...

A beam of electromagnetic radiation of intensity 6.4 × 10–5 W/cm2 is comprised of wavelength,
$$\lambda $$ = 310 nm. It falls normally on a metal (wor...