Dawn of Modern Physics

In photoelectric effect, removal of photons is observed at _______ energies.

At high temperature, the proportion of _______ wavelength radiation increases.

For photons of energy greater than 1.02 MeV the probability of pair production occurrence ______ as the energy increases.

Speed of light, radio waves and microwaves in vacuum is:

For intermediate energy of radiations, the dominant process is:

In Compton Effect, the value of is given by:

The value of Stefan's Boltzmann Constant is:

If R₁ = 10 kΩ and R₂ = 100 kΩ then the gain of op-amplifier as inverting amplifier is:

The life time of an electron in an excited state is about 10-8 s. What is its uncertainty in energy during this time?

In pair production, the type of photon used:

The minimum frequency below which no electron is emitted from the metal surface is called:

The value of Wien’s constant is:

The wavelength of γ-rays is:

The momentum of wave where wavelength is 1.32 x 10^-9 m:

The frequency of photon having momentum 4.42 x 10^-26 Ns is:

The Balmer series of hydrogen spectrum appears in the

The wave that has the highest frequency and penetrating power is

The speed of light in the vacuum is the same for all observers regardless of their relative motion or the motion of the source of the light", is the important postulate of:

In a photoelectric effect experiment the stopping potential is:

If the wavelength of incident radiation in a photoelectric experiment is decreased then

The momentum of a photon is 3.3×10−29 kg−m/sec. Its frequency will be

When placed in light which of the following can generate an output voltage across its electrodes?

Which of the following believed in absolute time?

In the photo-electric effect, electrons are emitted on incidence of light upon certain material surfaces:

Let an electron beam be accelerated by adjustable potential V. If we decrease potential V, the wavelength of the matter wave associated with the electron will:

Electrons of mass m and charge e are accelerated through a potential difference V and strike the target. The maximum speed of these electrons is:

Photoelectron emission depends upon the:

Black body is an ideal radiator that radiates ................. at all wavelengths.

As per 2nd photoelectric experiment, photoelectric effect does not occur if the frequency of the incident light is?

The momentum of moving photon is:

Which one of the following factors is the best for calculating Compton's shift?

The kinetic energy of emitted electrons in photoelectric effect can be increased by increasing _

At what angle made by scattered photons with x-axis , we can get the maximum value of Compton's shift?

Light propagates through space as a wave is evident by all of the following EXCEPT:

The de-Broglie wavelength associated with a particle moving at 10⁶ m/s and having mass 10⁻³⁰ kg:

The value of Planck constant is:

In Einstein's photoelectric equation hv =ϕ +eV, the kinetic energy of photoelectrons is:

In the mathematical relationship Φ = hv, the symbol Φ represents:

The speed of electromagnetic waves 'e' in free space is:

The ratio of'molar gas constant' to 'Avogadro's number' (R/Na) is called:

The units of the equation of Compton's scattering ∆λ = h/mc(1-cos) are of:

Positron and electron anhilate into:

Which photon is traveling with the largest speed in a vacuum?

In pair annihilation, two gamma-ray photons created, travel in opposite directions not in the same direction, because:

In a photoelectric effect experiment, the stopping potential is:

If electron, proton, neutron, and alpha particle have same velocity which of them have shortest wavelength?

The experimental proof of particle nature of light is:

The minimum energy of photon for pair production is:

The energy of each photon with frequency 1.2×10^14 H_z will be:

The rest mass of photon is:

De Broglie received the Nobel Prize in the year:

According to the wave-particle duality, identify respectively how all micro-particles (electrons, protons, atoms, etc) behave when propagating and when exchanging energies

Which of the following has the largest energy?

What is the rest mass of a photon?

The Compton's effect is the phenomenon that describes

In special theory of relativity, the law of conservation of energy and law of conservation of mass have been replaced with

In photodiode, the bias voltage is applied in bias form:

If frequency of light is greater than threshold frequency, then in photoelectric effect the number of electrons increases with an increase in _ of light :

In Compton effect, a photon of a certain wavelength collides with a stationary electron. The wavelength of the emitted photon is:

In Compton effect, the incident photon when compared to the scattered photon is of:

The process of ejection of loosely bound electrons from a certain photo sensitive surface by absorption of photon is called:

An atom makes a transition from a state of energy E₂ to one of lower energy E₁. Which of the following gives the wavelength of the radiation emitted, in terms of the Planck's constant h and the speed of light e?

Which of the following corresponds to the momentum of a photon?

If K₁ and K₂ are the maximum kinetic energies of photoelectrons emitted when lights of wavelength λ1 and λ2 respectively incident on a metallic surface and λ1 = 3λ2, then:

The frequency of incident light falling on a photo sensitive plate is doubled, then maximum kinetic energy of the emitted photoelectrons will become:

The surface of a metal is illuminated with a light of 400 nm. The kinetic energy of the ejected photoelectrons was found to be 1.68 eV. The work function of the metal is: (hc = 1240 eV.nm)

When photons of energy hv are incident on the surface of photosensitive material of work function hv0, then:

The work function of a metal is 1 eV. Light of wavelength 3000 Å is incident on this metal surface. The velocity of the emitted photo-electrons will be:

If two photons interact in same direction what will change?

In Compton's effect the wavelength of the scattered X-rays is

According to the special theory of relativity, mass of a moving object is considered as infinite when it moves with

The keynote of Einstein's theory of relativity is that gravity is a property of

The special theory of relativity is based upon I) The laws of physics are same in all inertial frame .II) The speed of light in free space has the same value for all observers, regardless of their state of motion.

FIX THIS:Identify the postulate /s which help to formulate a mathematical model of gases. i) A finite volume of gas consists of very large number of molecules ii) The size of the molecules in much smaller than the separation between molecules. iii) Molecules do not exert force on each other except during a collision

Which of the following physical phenomena connot be described only by the wave theory of the electromagnetic radiation?

When electron absorbs a photon and jumps to higher states it is called:

Blackbody shows a _ spectra:

Photons of energy 10.25 eV fall on the surface of the metal emitting photoelectrons of maximum kinetic energy 5.0 eV. What is the stopping voltage required for these electrons?

In annihilation process particles move in:

The word radiation means:

A body at temperature T radiates heat according to relation:

If the temperature of Sun is doubled, heat energy reached on earth become:

Wave particle duality does not describe:

X-ray is the reverse process of:

Wave nature and particle nature of photon is linked by:

Work function for a certain surface is 3.3 ev. Minimum frequency, light must have in order to eject electron from surface will be:

In order to increase the stopping potential, there should be increase in

The transverse nature of light is shown by

The rest mass of Photon is 𝑚𝑜. Its linear momentum, when it moves with the speed equal to half of the speed of light in space, will be:

Which of the following will be a better shield against 𝛾-rays?

The ionization potential of a hydrogen atom is 13.6V what will be the energy of the electron in the second orbit?

The maximum energy of the electrons released in photocell is independent of:

What is the momentum of X −rays having wavelength 0.001nm?

If we use a light of photons having energy 2.4 eV then the stopping potential required will be:

When light has exactly the same energy as the work done function of a metal surface then:

The de Broglie wavelength of a particle of mass 1 gram and velocity 100 ms^-1 is:

When electrons lose all their kinetic energy in the first collision, the entire kinetic appears as an X-ray photon of energy:

What is meant by spontaneous emission of electrons in solids?

If ‘m’ is the mass, ‘c’ is the velocity of light and x = mc2, then dimensions of ‘x’ will be:

The kinetic energy K.E. with which the electron strikes the target is given by:

In X-ray tube, electrons after being accelerated through velocity ‘v’ strike the target, then the wavelength of emitted X-rays is:

Work function was given by:

X-rays are also called:

When an electron releases energy and jumps from higher to lower energy state, it is called:

X-rays are:

Radiations are _ by a black body.

What is the value of the planck's constant?

The momentum of a photon is:

The bound state electron has a _.

The wavelength of a matter wave is independent of _.

In the case of a spectrometer, a circular scale graduated in half a degree is attached with _.

The black body always _ radiations.

Gamma rays travel _ distance.

Radiation can cause _.

Which light has more velocity?

The photoelectric effect is not possible with _ photons.

What is the de Broglie wavelength associated with an electron, accelerated through a potential difference of 200 volts?

-------- is conserved in pair production.

The photon is the particle, which has:

The inertial frame has:

In a subatomic world, things can be predicted with _ precision.

The frame of reference could be

Galilean transformations are applicable to:

In medical scanning, which rays are used?

Which radiation passes through black body

Which among the following phenomenon shows particle nature of light?

In pair production .................... are produced?

The linear momentum of a 3 MeV photon is?

Which principle is used in solar cells?

From the following properties of a wave, the one that is independent of the other three is its?

The photon when scattered from a mirror, its change in momentum becomes _.

What will be the photon energy for a wavelength of 5000 angstroms, if the energy of a photon corresponding to a wavelength of 7000 angstroms is 4.23 x 10^-19 J?

Number of electrons emitted in the photoelectric effect depends upon _.

For atomic spectra, atomic gas or vapor at a pressure that is much _ than atmospheric pressure is excited.

The number of electrons emitted in the photoelectric effect depends upon:

The wavelength of a matter wave is independent of:

Mass and energy are related to each other by:

Platinum wire becomes yellow at a temperature of _ degree C.

A black body is considered ideal when it _.

The existence of photons was confirmed by:

Which of these is conserved in solar cells?

Wave-particle duality does not explain:

The frequency of the incident photon after the Compton effect will:

A black body is considered ideal when it:

If a nucleus releases gamma rays its mass becomes:

X-rays images are detected on a _ screen.

Calculate the energy of a photon of wavelength 6600 angstroms.

According to Einstein, mass and energy are:

The black body which is most close to a perfect body is:

The momentum of white light is _ than X-rays.

The X-ray photon is uncertain when it is:

The range of wavelength of visible light is:

The spectrum of the black body is:

In Compton׳s scattering process, the wavelength of scattered X-rays :

What is the de Broglie wavelength of a ball of mass 150 g moving at a speed of 50 m/s?

What will be the De-Broglie wavelength when the kinetic energy of the electron increases by 5 times?

What is the frequency of a photon whose energy is 66.3 eV?

The number of photoelectrons emitted from metal depends upon:

The sun gives light at the rate of 1500 W/m² of area perpendicular to the direction of light. Assume the wavelength of light as 5000 Å. Calculate the number of photons/s arriving at 1 m² area at that part of the earth.

In wave motion, the least distance between two points that are out of phase of π radians is:

Among the following four spectral regions, in which of them, does the photon have the highest energy?

The reverse process of pair production is known as:

The energy of an electron in the nth orbit of a hydrogen atom is?

Black body radiations are:

Pair production is possible in _ Photon.

X-rays can be deflected by?

Where does the energy lost by fast-moving electrons go?

If two photons interact in the same direction what will change:

Michelson determined the velocity of light by:

Which of the following blocks will release heat fast?

Identify the de Broglie expression from the following.

When photons strikes with Al plate which electron is emitted?

Polarization explains light is _.

The linear momentum of a 3 Me V photon is:

Beta particle is actually a _.

Which is not the result of the special theory of relativity?

The momentum of the moving photon is _.

The energy of a photon is directly proportional to its _.

The spectrum of perfect black body is?

Einstein was given a Nobel prize for:

Fluorescence is produced when anode rays strike on:

The spin of a photon is:

What will the de Broglie wavelength of a 150 g mass moving with a velocity of 50 m/s be?

Photoelectric effect is not produced by:

A photosensitive material would emit electrons if it is excited by a photon beyond a threshold. To cross the threshold, what should be increased?

Compton shift is maximum at:

Which light photon has the least momentum?

Planck's constant is analogous to:

The photocell is similar to:

Calculate the energy of a photon of wavelength 6600 Angstroms:

Light photons, each of energy 3.5 x 10-19J falls on the cathode of a photocell. The current through the cell is reduced to zero by taking the cathode to a potential +0.25 V relative to anode. The work function of the cathode is:

The de Broglie wavelength of an electron travelling with a speed of 1.0 x 107m/s is equal to, (h=6.6 x 10-34 Js and me= 9.1 x 10-31 kg)

A 5 watt LED bulb converts 80% of the power into light photons wavelength 660 nm. What is the number of photons emitted from the bulb in one second.

Momentum of a photon is?

The value and units of the Planck constant ‘h’ can be expressed as:

Calculate the energy of a photon, with a frequency of 3.0 x 1018 H_z.(h = 6.63 x 10-34)

The existence of positron was discovered in the:

X-rays are used to investigate:

Plank׳s constant is analogus to:

The electron shows purely a _ when free.

The concept of work function was given by:

Photocell is similar to:

White light gives spectrum after undergoing:

Which group consists of only electromagnetic waves?

The uncertainty in momentum and position is due to its:

The charge of a photon is:

If the time interval between the occurrence of two events is measured in a frame with no relative motion in which two events occur. Then the time measured by the observer in a frame moving with relative velocity v is _.

An electron moving with velocity v has momentum 3 x 10 -26 Kg.m/s. The de Broglie wavelength associated with it is _. Value of h = 6.63 x 10-34 is.

The Bohr’s postulate for stationary orbits of H_ydrogen atoms _. Here m is the mass of the electron, v velocity, r orbital, and h is Planck's constant.

In order to produce pair production the minimum energy of photon required is:

In the Compton Scattering experiment the X-ray wavelength change Δλ is _. Here h is Planck constant, m rest mass of electron and θ is angle after scattering.

When an observer moves with velocity of light, relative to a timing device at rest, he would notice:

The number of LED segments used in a calculator display:

As the temperature of the black body is raised, the black body radiations become richer in:

According to Einstein, bodies and light rays follow a:

Physics is an experimental science which depends heavily on:

When photons are incident on a metal, electrons are emitted. The process is called:

What will be the energy of an X-ray quantum of wave length 1.0 x 10-10 m?

Electromagnetic wave theory was proposed by:

Minimum frequency below which no electrons are emitted from the metal surface is called _ frequency.

What will be the energy in Joules, when an electron acquires a speed of 10 m/s?

When an electron and its anti particle position come close enough to each other, they Completely convert into radiation energy in the form of photons, this process Is called:

The phenomena in which certain metals emit electrons when exposed to high-frequency light is known as?

The series limit for the Balmer series of hydrogen spectrum occurs at 3664 A°. Calculate Ionization energy of hydrogen atom.

Candela is the luminous intensity, in the perpendicular direction of a surface _ square meter of a black body at the temperature of freezing platinum under a pressure of 101325 newtons per square meter.

Gamma-ray (𝝲) can produce ionization in which of the following way/s?I. It may lose all its energy in a single encounter with the electron of an atom (Photoelectric effect).II. It may lose only a part of its energy in an encounter (Compton effect).III. Very few very high energy 𝝲 ray photons may impinge directly on heavy nuclei, be stopped and annihilated giving rise to electron-positron pairs (The materialization of energy).

The energy of an X-ray quantum of wavelength 1.0 x 10-10 m is:

If frequency of incident light is increased beyond threshold frequency, keeping light intensity constant, then:

In photo-emission from a metal, if light of λ is replaced by light of wavelength λ / 4 , the maximum kinetic energy of the photoelectrons.

Minimum energy required to eject an electron from metal surface is called: