English

If the total energy of radiation of frequency 1014 Hz is 6.63 J, Calculate the number of photons in the radiation. - Physics

Advertisements
Advertisements

Question

If the total energy of radiation of frequency 1014 Hz is 6.63 J, Calculate the number of photons in the radiation. 

Sum
Advertisements

Solution

Given:

E = 6.63 J, ν = 1014 Hz,
We know, h = 6.63 × 10–34 Js.

To find: Number of photons (n)   

Formula: n = `"E"/"hv"`

Calculation:

Using formula,

n = `6.63/(6.63 xx 10^-34 xx 10^14)`

∴ n = 1020 

The number of photons emitted in the radiation is 1020.  

shaalaa.com
The Photoelectric Effect
  Is there an error in this question or solution?
Chapter 14: Dual Nature Of Radiation And Matter - Short Answer I

APPEARS IN

SCERT Maharashtra Physics [English] 12 Standard HSC
Chapter 14 Dual Nature Of Radiation And Matter
Short Answer I | Q 5

RELATED QUESTIONS

Is it always possible to see the photoelectric effect with a red light?


Observations from an experiment on the photoelectric effect for the stopping potential by varying the incident frequency were plotted. The slope of the linear curve was found to be approximately 4.1 × 10−15 V s. Given that Exercises the charge of an electron is 1.6 × 10−19 C, find the value of the Planck’s constant h.

The threshold wavelength of tungsten is 2.76 x 10-5 cm.
(a) Explain why no photoelectrons are emitted when the wavelength is more than 2.76 x 10-5 cm.
(b) What will be the maximum kinetic energy of electrons ejected in each of the following cases

(i) if ultraviolet radiation of wavelength λ = 1.80 × 10-5 cm and
(ii) radiation of frequency 4 x 1015 Hz is made incident on the tungsten surface?


Given the following data for incident wavelength and the stopping potential obtained from an experiment on the photoelectric effect, estimate the value of Planck's constant and the work function of the cathode material. What is the threshold frequency and corresponding wavelength? What is the most likely metal used for emitter?

Incident wavelength (in Å) 2536 3650
Stopping potential
(in V)
1.95 0.5

As the intensity of incident light increases ______ 


Planck's constant is 6.6 × 10-34 Js. The momentum of each photon is given radiation Is 3.3 × 10-29 kg/s. The λ of radiation is ______.


Find the kinetic energy of the emitted electron, if in photoelectric effect energy of incident Photon is 4 eV and work function is 2.4 eV. 


What is the photoelectric effect? Define stopping potential and photoelectric work function. 


The energy of the incident photon on the metal surface is 3 W and then 5 W, where W is the work function for that metal. The ratio of velocities of emitted photoelectrons is ______.


The kinetic energy of the most energetic photoelectron emitted from a metal surface is doubled when the wavelength of the incident radiation is reduced from λ1 to λ2. The work function of the metal is ______


The maximum velocity of the photoelectron emitted by the metal surface is 'v '. Charge and mass of the photoelectron is denoted by 'e' and 'm' respectively. The stopping potential in volt is ______.


The work function of a metallic surface is 5.01 eV. The photoelectrons are emitted when light of wavelength 2000 Å falls on it. The potential difference applied to stop the fastest photoelectrons is [h = 4.14 x 10-15 eV sec] ____________.


When certain metal surface is illuminated with a light of wavelength A., the stopping potential is V, When the same surface is illuminated by light of wavelength 2λ, the stopping potential is `("V"/3)`. The threshold wavelength for the surface is ______.


When light of wavelength 'λ' is incident on a photosensitive surface, the stopping potential is 'V'. When light of wavelength '3λ' is incident on the same surface, the stopping potential is `"V"/6`. Threshold wavelength for the surface is _______.


Photoelectrons are emitted from a photosensitive surface for the light of wavelengths λ1 = 360 nm and λ2 = 600 nm. What is the ratio of work functions for lights of wavelength 'λ1' to 'λ2'?


When a surface 1 cm thick is illuminated by light of wavelength 'λ', the stopping potential is 'V0'. When the same surface is illuminated by light of wavelength '3λ', the stopping potential is `"V"_0/6`. The threshold wavelength for the metallic surface is ______.


Light of different frequencies, whose photons have energies 3 eV and 18 eV respectively, successively illuminate a metal of work function 2 eV. The ratio of the maximum speeds of the emitted electrons will be ______.


The photon of frequency vis incident on a metal surface whose threshold frequency is v0. The kinetic energy of the emitted photoelectrons will be ____________.


Which one of the following statements ts INCORRECT for stopping potential in photoelectric emission?


A light of wavelength '`lambda`' and intensity 'I' falls on photosensitive material. If 'N' photoelectrons are emitted, each with kinetic energy E, then ____________.


When the work function of a metal increases, maximum kinetic energy of emitted photoelectrons ____________.


The radiation corresponding to the 3 → 2 transition of a hydrogen atom falls on a gold surface to generate photoelectrons. These electrons are passed through a magnetic field of 5 × 10-4 T. Assume that the radius of the largest circular path followed by these electrons is 7 mm, and the work function of the metal is ______.

(Mass of electron = 9.1 × 10-31 kg)


When radiation of wavelength λ is used to illuminate a metallic surface, the stopping potential is V. When the same surface is illuminated with radiation of wavelength 3λ, the stopping potential is `"V"/4`. If the threshold wavelength for the metallic surface is nλ. then value of n will be ______.


We wish to observe an object which is 2.5Å in size. The minimum energy photon that can be used ______.


Light of wavelength λ, which is less than threshold wavelength is incident on a photosensitive material. If incident wavelength is decreased so that emitted photoelectrons are moving with same velocity, then stopping potential will ______.


If the maximum kinetic energy of emitted electrons in the photoelectric effect is 2eV, the stopping potential will be ______.


Define photoelectric work function of a metal.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×