## MCQ (Single Correct Answer)

The de Broglie wavelength associated with an electron, accelerated by a potential difference of 81 V is given by:

The maximum kinetic energy of the emitted photoelectrons in photoelectric effect is independent of:

The work functions of Caesium $$(\mathrm{Cs})$$, potassium $$(\mathrm{K})$$ and Sodium (Na) are $$2.14 ~\mathrm{eV}, 2.30 ~\mathrm{eV}$$ and $$2.75 ~\...

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

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 ...

The threshold frequency of a photoelectric metal is v0. If light of frequency 4v0 is incident on this metal, then the maximum kinetic energy of emitte...

When two monochromatic lights of frequency, v and $${v \over 2}$$ are incident on a photoelectric metal, their stopping potential becomes $${{{V_s}} \...

The number of photons per second on an average emitted by the source of monochromatic light of wavelength 600nm, when it delivers the power of 3.3 $$\...

An electromagnetic wave of wavelength '$$\lambda$$' is incident on a photosensitive surface of negligible work function. If 'm' mass is of photoelectr...

A radioactive nucleus $$_Z^AX$$ $$\to$$ $${}_{Z - 1}B$$ $$\to$$ $${}_{Z - 3}C$$ $$\to$$ $${}_{Z - 2}D$$, where Z is the atomic number of element X. Th...

Light of frequency 1.5 times the threshold frequency is incident on a photosensitive material. What will be the photoelectric current if the frequency...

An electron is accelerated from rest through a potential difference of V volt. If the de-Broglie wavelength of the electron is 1.227 $$ \times $$ 10-2...

An electron is accelerated through a potential difference of 10,000 V. Its de Broglie wavelength is (nearly) : (me = 9 $$ \times $$ 10–31 kg) ...

An electron of mass m with an initial velocity
$$\overrightarrow v = {v_0}\widehat i$$ (v0 > 0)
enters an electric field
$$\overrightarrow E = ...

When the light of frequency 2$${\upsilon _0}$$
(where $${\upsilon _0}$$
is
threshold frequency), is incident on a metal
plate, the maximum velocity ...

The de-Broglie wavelength of a neutron in thermal equilibrium with heavy water at a temperature T (kelvin) and mass m, is

Photons with energy 5 eV are incifent on a cathode C in a photoelectric cell. The maximum energy of emitted photoelectrons is 2 eV. When photons of en...

Electrons of mass m with de-Broglie wavelength $$\lambda $$ fall on the target in an X-ray tube. The cutoff wavelength ($$\lambda $$0) of the emitted ...

When a metallic surface is illuminated with radiation of wavelength $$\lambda $$, the stopping potential is V. If the same surface is illuminated with...

An electron of mass m and a photon have same energy E. The ratio of de-Broglie wavelengths associated with them is

Light of wavelength 500 nm is incifent on a metal with work function 2.28 eV. The de Broglie wavelength of the emitted electron is

A photoelectric surface is illuminated successively by monochromatic light of wavelength $$\lambda $$ and If the maximum kinetic energy of the emitted...

A certain metallic surface is illuminated with monochromatic light of wavelength, $$\lambda .$$ The stopping potential for photo-electric current for ...

Which of the following figures represent the variation of particle momentum and the associated de-Broglie wavelength?

When the energy of the incident radiation is increased nby 20%, the kinetic energy of the photoelectrons emitted from a metal surface increased from 0...

If the kinetic energy of the particle is increased to 16 times its previous value, the percentage change in the de Broglie wavelength of the particle ...

A source of light is placed at a distance of 50 cm from a photo cell and the stopping potential is found to be V0. If the distance between the light s...

The de-broglie wavelength of neutrons in thermal equilibrium at temperature T is

For photoelectric emission from certain metal the cutoff frequency is $$\upsilon $$. If radiation of frequency 2$$\upsilon $$ impinges on the metal pl...

The wavelength $$\lambda $$e of an electron and $$\lambda $$p of a photon of same energy E are related by

Two radiations of photons energies 1 eV and 2.5 eV, successively illuminate a photosensitive metallic surface of work function 0.5 eV. The ratio of th...

If the momentum of an electron is changed by P, then the de Broglie wavelength associated with changes by 0.5%. The initial momentum of electron will ...

Monochromatic radiation emitted when electron on hydrogen atom jumps from first excited to the ground state irradiates a photosensitive material. The ...

A 200 W sodium street lamp emits yellow light of wavelength 0.6 $$\mu $$m. Assuming it to be 25% efficient in converting electrical energy to light, t...

An $$\alpha $$-particle moves in a circular path of radius 0.83 cm in the presence of a magnetic field of 0.25 Wb/m2. The de Broglie wavelength associ...

The threshold frequency for a photosensitive metal is 3.3 $$ \times $$ 1014 Hz. If light of frequency 8.2 $$ \times $$ 1014 Hz is incident on this met...

In the Davisson and Germer experiment, the velocity of electrons emitted from the electron gun can be increased by

Photoelectric emission occurs only when the incident light has more than a certain minimum

Light of two different frequencies whose photons have energies 1 eV and 2.5 eV respectively illuminate a metallic surface whose work function is 0.5 e...

Electrons used in an electron microscope are accelerated by a voltage of 25 kV. If the voltage is increased to 100 kV then the de-Broglie wavelength a...

In photoelectric emission process from a metal of work function 1.8 eV, the kinetic energy of most energetic electrons is 0.5 eV. The corresponding st...

When monochromatic radiation of intensity $$I$$ falls on a metal surface, the number of photoelectrons and their maximum kinetic energy are N and T re...

The electron in the hydrogen atom jumps from excited state (n = 3) to its ground state (n = 1) and the photons thus emitted irradiate a photosensitive...

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 ...

The potential difference that must be applied to stop the fastest photoelectrons emitted by a nickel surface, having work functions 5.01 eV, when ultr...

A source S1 is producing, 1015 photons per second of wavelength 5000 $$\mathop A\limits^ \circ $$. Another source S2 is producing 1.02 $$ \times $$ 1...

The number of photo electrons emitted for light of a frequency $$\upsilon $$ (higher than the threshold frequency $${\upsilon _0}$$) is proportional t...

Monochromatic light of wavelength 667 nm is produced by a helium neon laser. The power emitted is 9 mW. The number of photons arriving per sec. on the...

The figure shows a plot of photo current versus anode potential for a photo sensitive surface for three different radiations. Which one of the followi...

A particle of mass 1 mg has the same wavelength as an electron moving with a velocity of 3 $$ \times $$ 106 m s$$-$$1. The velocity of the particle is...

The work function of a surface of a photosensitive material is 6.2 eV. The wavelength of the incident radiation for which the stopping potential is 5 ...

In the phenomenon of electric discharge through gases at low pressure, the coloured glow in the tube appears as a result of

A 5 watt source emits monochromatic light of wavelength 5000 $$\mathop A\limits^ \circ $$. When placed 0.5 m away, it liberates photoelectrons from a...

A beam of electron passes undeflected through mutually perpendicular electric and magnetic fields. If the electric field is switched off, and the same...

Monochromatic light of frequency 6.0 $$ \times $$ 1014 Hz is produced by a laser. The power emitted is 2 $$ \times $$ 10$$-$$3 W. The number of photon...

When photons of energy h$$\upsilon $$ fall on an aluminimum plate (of work function E0), photoelectrons of maximum kinetic energy K are ejected. If th...

A photocell employs photoelectric effect to convert

The momentum of a photon of energy 1 MeV in kg m/s will be

In a discharge tube ionization of enclosed gas is produced due to collisions between

The work functions for metals A, B and C are respectively 1.92 eV, 2.0 eV and 5 eV. According to Einstein's equation the metals which will emit photoe...

A photosensitive metallic surface has work function, h$$\upsilon $$0. If photons of energy $$2h{\upsilon _0}$$ fall on this surface, the electrons com...

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

A photoelectric cell is illuminated by a point source of light 1 m away. When the source is shifted to 2 m then

J.J. Thomson's cathode-ray tube experiment demonstrated that

Which of the following is not the property of cathode rays ?

When ultraviolet rays incident on metal plate then photoelectric effect does not occur, it occurs by incidence of

If particles are moving with same velocity, then which has maximum de Broglie wavelength?

The value of Planck's constant is

In Thomson mass spectrograph $$\overrightarrow E \bot \overrightarrow B $$ then the velocity of electron beam will be

Which one among the following shows particle nature of light?

A photo-cell is illuminated by a source of light, which is placed at a distance d from the cell. If the distance become d/2, then number of electrons ...

By photoelectric effect, Einstein proved

Who evaluated the mass of electron infirectly with help of charge

## MCQ (More than One Correct Answer)

The photoelectric threshold wavelength of silver is 3250 $$ \times $$ 10$$-$$10 m. The velocity of the electron ejected from a silver surface by ultra...