Calculate the momentum of a photon of light of wavelength 500nm.
Question types
Photoelectric Effect and WaveParticle Duality question types
68 questions across 6 question groups — pick any mix to generate a Physics paper with step-by-step answer keys.
68
Questions
6
Question groups
5
Question types
01
2 Marks Questions
6 Q→023 Marks Question
15 Q→031 Marks Question
5 Q→044 Marks Questions
2 Q→05M.C.Q (1 Marks)
20 Q→065 Marks Questions
20 Q→Sample Questions
Photoelectric Effect and WaveParticle Duality questions
One sample from each question group in this chapter. Select any group above to see the full set with answer keys.
View full solution →
A parallel beam of monochromatic light of wavelength 663nm is incident on a totally reflecting plane mirror. The angle of incidence is 60° and the number of photons striking the mirror per second is 1.0 × 1019. Calculate the force exerted by the light beam on the mirror.
A photographic film is coated with a silver bromide layer. When light fells on this film, silver bromide molecules dissociate end the film records the light there. A minimum of 0.6eV is needed to dissociate a silver bromide molecule. Find the maximum wavelength of light that can be recorded by the film.
Find the maximum kinetic energy of the photoelectrons ejected when light of wavelength 350nm is incident on a cesium surface. Work function of cesium = 1.9eV
If an electron has a wavelength, does it also have a colour?
It is found that photosynthesis starts in certain plants when exposed to the sunlight but it does not start if the plant is exposed only to infrared light. Explain.
Should the energy of a photon be called its kinetic energy or its internal energy?
Calculate the number of photons emitted per second by a 10W sodium vapour lamp. Assume that 60% of the consumed energy is converted into light. Wavelength of sodium light = 590nm.
Show that it is not possible for a photon to be completely absorbed by a free electron.
Two neutral particles are kept 1m apart. Suppose by some mechanism some charge is transferred from one particle to the other and the electric potential energy lost is completely converted into a photon. Calculate the longest and the next smaller wavelength of the photon possible.
In an experiment on photoelectric effect, a photon is incident on an electron from one direction and the photoelectron is emitted almost in the opposite direction. Does this violate conservation of momentu?
Can a photon be deflected by an electric field? By a magnetic field?
The threshold wavelength of a metal is $\lambda_0.$ Light of wavelength slightly less $\tan \lambda_0.$ is incident on an insulated plate made of this metal. It is found that photoelectrons are emitted for some time and after that the emission stops. Explain.
View full solution →Consider the situation described in the previous problem. Show that the force on the sphere due to the light falling on it is the same even if the sphere is not perfectly absorbing.
A sphere of radius 1.00cm is placed in the path of a parallel beam of light of large aperture. The intensity of the light is 0.5W/cm-2. If the sphere completely absorbs the radiation falling on it, find the force exerted by the light beam on the sphere.
A hot body is placed in a closed room maintained at a lower temperature. Is the number of photons in the room increasing?
A silver ball of radius 4.8cm is suspended by a thread in a vacuum chamber. Ultraviolet light of wavelength 200 run is incident on the ball for some time during which a total light energy of 1.0 × 10-7J falls on the surface. Assuming that on the average one photon out of every ten thousand is able to eject a photoelectron, find the electric potential et the surface of the bell assuming zero potential at infinity. What is the potential at the centre of the bell?
The work function of a metal is hv0. Light of frequency v falls on this metal. The photoelectric effect will take place only if:
View full solution →-
$\text{v}\geq\text{v}_0$
-
$\text{v}>2\text{v}_0$
-
$\text{v}<\text{v}_0$
-
$\text{v}<\frac{\text{v}_0}{2}$
Light of wavelength $\lambda$ falls on a metal having work function $\frac{\text{h}_\text{c}}{\lambda_0}.$ Photoelectric effect will take place only if:
View full solution →-
$\lambda\geq\lambda_0$
-
$\lambda\geq2\lambda_0$
-
$\lambda\leq\lambda_0$
-
$\lambda<\frac{\lambda_ 0}{2}.$
A proton and an electron are accelerated by the same potential difference. Let $\lambda_\text{e}$ and $\lambda_\text{p}$ denote the de Broglie wavelengths of the electron and the proton respectively.
View full solution →-
$\lambda_\text{e}=\lambda_\text{p}.$
-
$\lambda_\text{e}<\lambda_\text{p}.$
-
$\lambda _\text{e}>\lambda_\text{p}.$
-
The relation between
Let p and E denote the linear momentum and energy of a photon. If the wavelength is decreased:
- Both p and E increase.
- P increases and E decreases.
- P decreases and E increases.
- Both p and E decrease.
If the frequency of light in a photoelectric experiment is doubled, the stopping potential will:
- Be doubled.
- Be halved.
- Become more than double.
- Become less than double.
It is found that yellow light does not eject photoelectrons from a metal. Is it advisable to try with orange light? With green light?
In an experiment on photoelectric effect, the stopping potential is measured for monochromatic light beams corresponding to different wavelengths. The data collected are 11s follows:
View full solution →| wavelength (nm) | 350 | 400 | 450 | 500 | 550 |
| stopping potential(V): | 1.45 | 1.00 | 0.66 | 0.38 | 0.16 |
Plot the stopping potential against inverse of wavelength
$\big(\frac{1}{\lambda}\big) $ on a graph paper and find- The Planck constant,
- The work function of the emitter and.
- The threshold wavelength.
A light beam of wavelength 400 run is incident on a metal plate of work function 2.2eV.
- A particular electron absorbs a photon and makes two collisions before coming out of the metal. Assuming that 10% of the extra energy is lost to the metal in each collision, find the kinetic energy of this electron as it comes out of the metal.
- Under the same assumptions, find the maximum number of collisions the electron can suffer before it becomes unable to come out of the metal.
The work function of a photoelectric material is 4.0eV.
- What is the threshold wavelength?
- Find the wavelength of light for which the stopping potential is 2.5V.
In an experiment on photoelectric effect, the emitter and the collector plates are placed et a separation of 10cm and are connected through en ammeter without any cell A magnetic field B exists parallel to the plates. The work function of the emitter is 2.39eV and the light incident on it has wavelengths between 400nm and 600nm. Find the minimum value of B for which the current registered by the ammeter is zero. Neglect any effect of space charge.
Generate a Photoelectric Effect and WaveParticle Duality paper free
Pick question groups from the list above, set marks and difficulty, and export a branded PDF with step-by-step answer keys. First 3 chapters free — no signup.