Light coming from a discharge tube fille...

Light coming from a discharge tube filled with hydrogen falls on the cathode of the photoelectric cell. The work function of the surface of cathode is 4eV Which one of the following values of the anode voltage (in volts ) with respect to the cathode willl likely to make the photoo current zero.

`-4`

`-6`

`-8`

`-10`

Text Solution

Verified by Experts

The correct Answer is:

Maximum photon energy `= 13.6 eV ("emitted")`
So `K_(max) = 13.6 - 4 = 9.6 eV`
Hence stopping potential is `- 9.6 V`
So `- 10 V` can stop

Topper's Solved these Questions

SIMPLE HARMONIC MOTION
ALLEN|Exercise Exercise-02|19 Videos
SIMPLE HARMONIC MOTION
ALLEN|Exercise Exercise- 3 Match The Column|1 Videos
SIMPLE HARMONIC MOTION
ALLEN|Exercise SOME WORKED OUT EXAMPLES|29 Videos
RACE
ALLEN|Exercise Basic Maths (Wave Motion & Dopplers Effect) (Stationary waves & doppler effect, beats)|24 Videos
TEST PAPER
ALLEN|Exercise PHYSICS|4 Videos

Similar Questions

Explore conceptually related problems

Light from a hydrogen tube is incident on the cathode of a photoelectric cell the work function of the cathode surface is 4.2 eV . In order to reduce the photo - current to zero the voltage of the anode relative to the cathode must be made

Light form a dicharge tube containing hydrogen atoms falls on the surface of a piece of sodium. The kinetic energy of the fastest photoelectrons emitted from sodium is 0.73 eV. The work function for sodium is 1.82 eV. Find (a) the energy of the photons causing the photoelectrons emission. (b) the quatum numbers of the two levels involved in the emission of these photons. (c ) the change in the angular momentum of the electron in the hydrogen atom, in the above transition, and (d) the recoil speed of the emitting atom assuming it to be at rest before the transition. (lonization potential of hydrogen is 13.6 eV.)

Light of wavelength lambda_(ph) falls on a cathode plate inside a vacuum tube as shown in the figure .The work function of the cathode surface is phi and the anode is a wire mesh of conducting material kept at distance d from the cathode. A potential different V is maintained between the electrodes. If the minimum de Broglie wavelength of the electrons passing through the anode is lambda_(e) which of the following statement (s) is (are) true?

de Broglie proposed dual nature for electron by putting his famous equation lambda = (h)/(mv). Later on, Heisenberg proposed uncertainty principle as deltapDeltax ge (h)/(4pi). On the contrary, Particle nature of electron was established on the basis of photoelectric effect. When a photon strikes the metal surface it gives up its energy to the electron. Part of this energy (say W) is used by the electrons to escape from the metal and the remaining energy imparts kinetic energy (1//2 mv^(2)) to the ejected photoelectron. The potential applied on the surface to reduce the velocity of photoelectron to zero is known as stopping potential . When a beam of photons of a particular energy was incident on a surface of a particular pure metal having work function =(40 eV), some emitted photoelectrons had stopping potential equal to 22 V. some had 12V and rest had lower values. Calculate the wavelength of incident photons assuming that at least one photoelectron is ejected with maximum possible kinetic energy :

A vacuum photocell consists of a central cathode and an anode. The internal surface is silver of work function 4.5 eV. The contact potential difference between the electrodes equals to 0.6 V. The photocell is illuminated by light of wavelength 2.3xx10^-7 m. a. What retrading potential difference should be applied between electrodes of the photocell for the photocurrent to drop to zero? b. If a retarding potential of 1V is applied between electrodes at what limiting wavelength lamda of light incident on the cathode will on the cathode will the photoelectric effect begin?

The graph between photo electric current and cathode potential when the anode is kept at zero potential, for light of two different intensities out of the same frequency looks like the one:

A point source is emitting 0.2 W of ultravio- let radiation at a wavelength of lambda = 2537 Å . This source is placed at a distance of 1.0 m from the cathode of a photoelectric cell. The cathode is made of potassium (Work function = 2.22 eV ) and has a surface area of 4 cm^(2) . (a) According to classical theory, what time of exposure to the radiation shall be required for a potassium atom to accumulate sufficient energy to eject a photoelectron. Assume that radius of each potassium atom is 2 Å and it absorbs all energy incident on it. (b) Photon flux is defined as number of light photons reaching the cathode in unit time. Calculate the photon flux. (c) Photo efficiency is defined as probability of a photon being successful in knocking out an electron from the metal surface. Calculate the saturation photocurrent in the cell assuming a photo efficiency of 0.1. (d) Find the cut – off potential difference for the cell.

The anode voltage of a photo cell is kept fixed. The wavelength lamda of the light falling on the cathode is gradually changed. The plate current I of the photo cell varies as follows

Monochromatic light of wavelength 198 nm is incident on the surface of a metallic cathode whose work function is 2-5 eV. How muchpotential difference must be applied between the cathode and the anode of a photocell to just stop the photo current from flowing?

The emission of electrons from a metal surface exposed rto light radaition of appropriate wavelength is called photoelectroic effect .The emmited electron are called photo=-weklectron work function of threshold energy may be defined as the minimum amount of energy required to ejercted electron from a most surface .According to Einstein Maximum kinetic energy of ejected electron = Aborbed energy - Work function (1)/(2) mv_(max)^(2) = h(v) - h(v_(n)) = hv [(1)/(lambda) -0 (1)/(lambda_(n))] Where v_(n) and lambda_(0) are thereshold frequency and threshold wavelength respectively Sopping potential : it is the miximum potential at which the photoelectric current becomes zero if V_(0) is the stopping potential eV_(0) = h(v- v_(0)) Whaich of the following is the graph between the frequency (V) of the incident radiation and the stopping potential (v) ?

ALLEN-SIMPLE HARMONIC MOTION-Exercise-01

Linear momenta of a proton and an electrons are euqal. Relative to an...
Text Solution
|
The wavelength of de-Brogile waves associted with neutrons at room tem...
Text Solution
|
Light coming from a discharge tube filled with hydrogen falls on the c...
Text Solution
|
If electron with principal quantum number n gt 4 were not allowed in n...
Text Solution
|
If 13.6 eV energy is required to lionize the hydrogen atm, then energy...
Text Solution
|
The diagram shows the energy levels for an electron in a certain atom....
Text Solution
|
The muon has the same change as an electron but a mass that is 207 tim...
Text Solution
|
In problems involving electromagenetism it is often convenlent and inf...
Text Solution
|
Which of the following transitions gives photon of maximum energy?
Text Solution
|
The velocity of an electron in single electron atom in an orbit
Text Solution
|
The energy level diagram is for a hypothetical atom. A gas of these at...
Text Solution
|
The wave number of the series limit of Lyman series is -
Text Solution
|
In a hypothetivsl system, a particle of mass m and charge -3q is movin...
Text Solution
|
The diagram to the right shows the lowest four energy levels for an el...
Text Solution
|
Energy of 24.6 eV is required to remove one of the electron from a neu...
Text Solution
|
A photon was absorbed by a hydrogen atom in its ground state and the e...
Text Solution
|
The K(alpha) X-ray emission line of tungsten occurs at lambda = 0.02 n...
Text Solution
|
Which of the following are the characterstics requried for the target ...
Text Solution
|
The wavelength of K(alpha) line for an element of atomic number 43 "is...
Text Solution
|
The Wavelengths of K(alpha) X - rays of two metals A and B are 4/(1875...
Text Solution
|