InterviewSolution
Saved Bookmarks
InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 101. |
The mass of a photo electron isA. `9.1 xx 10^(-27) kg`B. `9.1 xx 10^(-29) kg`C. `9.1 xx 10^(-31)` kgD. `9.1 xx 10^(-34) kg` |
|
Answer» Correct Answer - C |
|
| 102. |
The retarding potential for having zero photo - electron currentA. Is proportional to the wavelength of incident lightB. Increases uniformly with the increase in the wavelength of incident lightC. Is proportional to the frequency of incident lightD. Increases uniformly with the increase in the frequency of incident light wave |
|
Answer» Correct Answer - D |
|
| 103. |
A metal surface of work function `1.07 eV` is irradiated with light of wavelength `332 nm`. The retarding potential required to stop the escape of photo - electrons isA. 4.81 eVB. 3.74 eVC. 2.66 eVD. 1.07 eV |
|
Answer» Correct Answer - C |
|
| 104. |
Consider the following two statements `A` and `B` and identify the correct choice `A)` When a rigid body is rotating about its own axis, at a given instant all particles of body posses same angular velocity. `B)` When a rigid body is rotating about its own axis, the linear velocity of a particle is directly proportional to its perpendicular distance from axisA. Both A and B are trueB. Both A and B are falseC. A is true but B is falseD. A is false B is true |
|
Answer» Correct Answer - D |
|
| 105. |
Two identical photocathodes receive light of frequency `f_(1) andf_(2)` if the velocites of the photo electrons (of mass `m`) coming out are repectively `v_(1) and v_(2)` thenA. `v_(1)-v_(2)=[(2h)/(m)(f_(1)-f_(2))]^(1//2)`B. `v_(1)^(2)-v_(2)^(2)=(2h)/(m)(f_(1)-f_(2))`C. `v_(1)+v_(2)=[(2h)/(m)(f_(1)+f_(2))]^(1//2)`D. `v_(1)^(2)+v_(2)^(2)=(2h)/(m)(f_(1)+f_(2))` |
|
Answer» Correct Answer - B |
|
| 106. |
The de - Broglie wavelength `lambda` associated with an electron having kinetic energy `E` is given by the expressionA. `(h)/(sqrt(2mE))`B. `(2h)/(mE)`C. `2mhE`D. `(2sqrt(2mE))/(h)` |
|
Answer» Correct Answer - A 1/2mv²=E mv=√2mE Therefore, E=h/mv = h/√2mE Therefore, Option A
|
|
| 107. |
The idea of matter waves was given byA. Davisson and GermerB. de-BroglieC. EinsteinD. Plank |
|
Answer» Correct Answer - B |
|
| 108. |
When the kinetic energy of an electron is increased , the wavelength of the associated wave willA. IncreasesB. DecreaseC. Wavelength doesnot depend on the kintic energyD. None of the above |
|
Answer» Correct Answer - B |
|
| 109. |
A wave is associated with matter when it isA. When it is stationaryB. When it is in motion with the velocity of light onlyC. When it is in motion with any velocityD. None of these |
|
Answer» Correct Answer - C |
|
| 110. |
The de - Broglie wavelength associated with the particle of mass `m` moving with velocity `v` isA. h/mvB. mv/hC. mh/vD. m/hv |
|
Answer» Correct Answer - A |
|
| 111. |
A photon , an electron and a uranium nucleus all have the same wavelength . The one with the most energyA. Is th photonB. Is the electronC. Is the uranium nucleusD. Depends upon the wavelength and the properties of the particle. |
|
Answer» Correct Answer - A |
|
| 112. |
Statement I : Penetration power of hard X-ray is more than that of soft X-ray. Statement II : Hard X-ray is used for engineering purpose while soft X-ray is used for medical purpose.A. VelocityB. IntensityC. FrequencyD. Polarization |
|
Answer» Correct Answer - C |
|
| 113. |
If the work function for a certain metal is `3.2 xx 10^(-19)` joule and it is illuminated with light of frequency `8 xx 10^(14) Hz`. The maximum kinetic energy of the photo-electrons would be `(h = 6.63 xx 10^(-34) Js)`A. `2.1 xx 10^(-19)J`B. `8.5 xx 10^(-9) J`C. `5.3 xx 10^(-19)J`D. `3.2 xx 10^(-19)J` |
|
Answer» Correct Answer - A |
|
| 114. |
The `X`- ray wavelength of `L_(alpha)` line of platinum `(Z = 78)` is `1.30 Å`. The `X` - ray wavelength of `L_(alpha)` line of Molybdenum `(Z = 42)` isA. 5.41 ÅB. 4.20 ÅC. 2.70 ÅD. 1.35 Å |
|
Answer» Correct Answer - A |
|
| 115. |
The wavelength of `K_(alpha)` line in copper is `1.54 Å`. The ionisation energy of `K` electron in copper in Joule isA. `11.2xx10^(-27)`B. `12.9 xx 10^(-16)`C. `1.7 x 10^(-15)`D. `10 xx 10^(-16)` |
|
Answer» Correct Answer - B |
|
| 116. |
A physicist wishes to eject electrons by shining light on a metal surface. The light source emits light of wavelength of 450 nm. The table lists the only available metals and their work functions. `{:("Metal",W_(0)(eV)),("Barium",2.5),("Lithium",2.3),("Tantalum",4.2),("Tungsten",4.5):}` Which metal(s) can be used to produce electrons by the photoelectric effect from given source of light?A. Barium onlyB. Barium or lithiumC. Lithium, tantanlum ot tungstenD. Tungsten or tantalum |
|
Answer» Correct Answer - B |
|
| 117. |
The photoelectric work function for a metal surface is `4.125 eV`. The cut - off wavelength for this surface isA. 4125 ÅB. 2062.5 ÅC. 3000 ÅD. 6000 Å |
|
Answer» Correct Answer - C |
|
| 118. |
In producing X-rays a beam of electrons accelerated by a potential difference V is made to strike a metal target. For what value of `V,X`-rays will have the lowest wavelength of 0.3094 ÅA. 10 kVB. 20 kVC. 30 kVD. 40 kV |
|
Answer» Correct Answer - D |
|
| 119. |
In radio theraphy, X-rays are used toA. Detect bone featuresB. Treat cancer by controlled exposureC. Detect heart diseaseD. Detec fault in radio receiving circuits. |
|
Answer» Correct Answer - B |
|
| 120. |
Figure represents the graph of photo current `l` versus applied voltage (V). The minimum energy of emitted photoelectrons is A. 2 eVB. 4 eVC. 0 eVD. 4 J |
|
Answer» Correct Answer - B |
|
| 121. |
The curves `(a) , (b) , ( c )` and `(d)` show the variation between the applied potential difference `(V)` and the photoelectric current `(i)` , at two different intensities of light `(I_(1) gt I_(2))`. In which figure is the correct variation shown ?A. B. C. D. |
|
Answer» Correct Answer - B |
|
| 122. |
For a photoelectric cell the graph showing the variation of cut of voltage `(V)` with frequency `(v)` of incident light is best represented byA. B. C. D. |
|
Answer» Correct Answer - D |
|
| 123. |
When a point source of light is at a distance of one metre from a photo cell , the cut off voltage is found to be `V`. If the same source is placed at `2 m` distance from photo cell , the cut off voltage will beA. VB. V/2C. V/4D. `V//sqrt(2)` |
|
Answer» Correct Answer - A |
|
| 124. |
A point source of light is used in an experiment on photoelectric effect . Which of the following curves best represents the variation of photo current (i) with distance (d) of the source from the emitter ? A. aB. bC. cD. d |
|
Answer» Correct Answer - D |
|
| 125. |
A photo cell is receiving light from a source placed at a distance of `1 m`. If the same source is to be placed at a distance of `2 m` , then the ejected electronA. moves with one-fouth energy as that of the initial energyB. moves with one-fourth of momemtum as that of the initial momentumC. will be half in numberD. will be one-fourth in number |
|
Answer» Correct Answer - D |
|
| 126. |
In photoelectric effect if the intensity of light is doubled then maximum kinetic energy of photoelectrons will becomeA. DoubleB. HalfC. Four timeD. No change |
|
Answer» Correct Answer - D |
|
| 127. |
For moving ball of cricket, the correct statement about de-Broglie wavelength isA. It is not applicable for such big particleB. `(h)/(sqrt(2mE))`C. `sqrt((h)/(2mE))`D. `(h)/(2mE)` |
|
Answer» Correct Answer - B |
|
| 128. |
In the following arrangement `y = 1.0 mm , d = 0.24 mm` and `D = 1.2 m`. The work function of the material of the emitter is `2.2 eV`. The stopping potential `V` needed to stop the photo current will be A. 0.9VB. 0.5VC. 0.4VD. 0.1V |
|
Answer» Correct Answer - A |
|
| 129. |
For production of characteristic `K_(beta) X - rays` , the electron transition isA. `n=2 "to" n=1`B. `n=3 "to" n=2`C. `n=3 "to" n=1`D. `n=4 "to" n=2` |
|
Answer» Correct Answer - C |
|
| 130. |
If the minimum wavelength obtained in an `X` - ray tube is `2.5 xx 10^(-10) m` , the operating potential of the tube will beA. 2 kVB. 3 kVC. 4 kVD. 5 kV |
|
Answer» Correct Answer - D |
|
| 131. |
In a photocell bichromatic light of wavelength `2475 Å` and `6000 Å` are incident on cathode whose work function is `4.8 eV`. If a uniform magnetic field of `3 xx 10^(-5) Tesla` exists parallel to the plate , the radius of the path describe by the photoelectron will be (mass of electron ` = 9 xx 10^(-31) kg`)A. 1 cmB. 5 cmC. 10 cmD. 25 cm |
|
Answer» Correct Answer - B |
|
| 132. |
Photon and electron are given same energy `(10^(-20) J)`. Wavelength associated with photon and electron are `lambda_(ph)` and `lambda_(el)` then correct statement will beA. `lamda_(Ph)gtlamda_(el)`B. `lamda_(Ph) lt lamda_(el)`C. `lamda_(Ph)=lamda_(el)`D. `(lamda_(el))/(lamda_(Ph))=C` |
|
Answer» Correct Answer - A |
|
| 133. |
Work function of lithium and copper are respectively `2.3 eV` and `4.0 eV`. Which one of the metal will be useful for the photoelectric cell working with visible light ? `(h = 6.6 xx 10^(-34) J - s, c = 3 xx 10^(8) m//s)`A. lithiumB. CopperC. BothD. None of these |
|
Answer» Correct Answer - A |
|
| 134. |
The work function of a certain metal is `(hC)/lambda_(0)`. When a monochromatic light of wavelength `lambda lt lambda_(0)` is incident such that the plate gains a total power `P`. If the efficiency of photoelectric emission is `eta%` and all the emitted photoelectrons are captured by a hollow conducting sphere of radius `R` already charged to potential `V`, then neglecting any interaction of potential of the sphere at time `t` is:A. `V+(100etalambdaPet)/(4piepsilonRhC)`B. `V-(etalambdaPet)/(400piepsilonRhC)`C. VD. `(lambdaPet)/(4piepsilonRhC)` |
|
Answer» Correct Answer - B |
|
| 135. |
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 madeA. `-4.2 V`B. `-9.4 V`C. `-17.8 V`D. `+9.4V` |
|
Answer» Correct Answer - B |
|
| 136. |
Photoelectric emission is observed from a metallic surface for frequencies `v_(1)` and `v_(2)` of the incident light rays `(v_(1) gt v_(2))`. If the maximum values of kinetic energy of the photoelectrons emitted in the two cases are in the ratio of `1 : k` , then the threshold frequency of the metallic surface isA. `(v_(1)-v_(2))/(k-1)`B. `(kv_(1)-v_(2))/(k-1)`C. `(kv_(2)-v_(1))/(k-1)`D. `(v_(2)-v_(1))/(k)` |
|
Answer» Correct Answer - B |
|
| 137. |
The cathode of a photoelectric cell is changed such that the work function changes from `(W_(1) to W_(2) (W_(2) gt W_(1))`. If the current before and after change are `I_(1)` and `I_(2)`, all other conditions remaining unchanged , then (assuming `hv gt W_(2)`)A. `I_(1) = I_(2)`B. `I_(1) lt I_(2)`C. `I_(1) gt I_(2)`D. `I_(1) lt I_(2) lt 2I_(1)` |
|
Answer» Correct Answer - A |
|
| 138. |
Assertion : The energy `(E )` and momentum `(p)` of a photon are related by `p = E//c`. Reason : The photon behaves like a particle.A. If both assertion and reason are true and the reason is the correct explanation of the assert ion.B. If both assertion and reason are true but reason is not the correct explanation of the assertion.C. If assertion is true but reason is false.D. If the assertion and reason both are false |
|
Answer» Correct Answer - A |
|
| 139. |
The momentum of a photon is `33 xx 10^(- 29) kg - m//sec`. Its frequency will beA. `3 xx 10^(3) Hz`B. `6 xx 10^(3) Hz`C. `7.5 xx 10^(12) Hz`D. `1.5 xx 10^(13) Hz` |
|
Answer» Correct Answer - D |
|
| 140. |
The X-rays produced in a coolidge tube of potential difference 40 V have minimum wavelength ofA. `3.09 xx 10^(-8) m`B. `5.09 xx 10^(8) m`C. `4.09 xx 10^(-8) m`D. `1.09 xx10^(8) m` |
|
Answer» Correct Answer - A |
|
| 141. |
Particle nature and wave nature of electromagnetic waves and electrons can be shown byA. Electron has small mass, deflected by the metal sheetB. X-ray is diffracted and defractedC. Light is refracted and defractedD. Photoelectricity and electron microscopy |
|
Answer» Correct Answer - D |
|
| 142. |
The collector of the photocell (in photoelectric experiment ) is made of tungsten while the emitter is Platinum having work function of `10 eV`.Monochromatic radiation of wavelength `124 Å` & power `100 ` watt is incident on emitter which emits photo electrons with a quantum efficiency of `1%`.The accelerating voltage acros the photocell is of `10,000` volts (Use: `hc=12400eV Å`) The minimum wavelength of radiation coming from the tungsten target (collector) is A. 124 ÅB. 1.24 ÅC. 1.23 ÅD. 12.3 Å |
|
Answer» Correct Answer - C |
|
| 143. |
What is the de - Broglie wavelength of the alpha - particle accelerated through a potential difference `V`?A. `(0.287)/(sqrt(V))Å`B. `(12.27)/(sqrt(V))Å`C. `(0.101)/(sqrt(V))Å`D. `(0.202)/(sqrt(V))Å` |
|
Answer» Correct Answer - C |
|
| 144. |
The fact that electric charges are integral multiples of the fundamental electronic charge was proved experimentally byA. PlanckB. J.J. ThomsonC. EinsteinD. Millikan |
|
Answer» Correct Answer - D |
|
| 145. |
Assertion : The phenomenon of `X` - ray production is basically inverse of photoelectric effect. Reason : `X` - rays are electromagnetic waves.A. If both assertion and reason are true and the reason is the correct explanation of the assert ion.B. If both assertion and reason are true but reason is not the correct explanation of the assertion.C. If assertion is true but reason is false.D. If the assertion and reason both are false |
|
Answer» Correct Answer - B |
|
| 146. |
The de - Broglie wavelength of a particle accelerated with `150 volt` "potential is" `10^(-10) m`. If it is accelerated by `600 volts p.d`., its wavelength will beA. 0.25 ÅB. 0.5 ÅC. 1.5 ÅD. 2 Å |
|
Answer» Correct Answer - B |
|
| 147. |
By photoelectric effect, Einstein, provedA. `E=hv`B. `K.E. = (1)/(2) mv^(2)`C. `E=mc^(2)`D. `E=(Rhc^(2))/(n^(2))` |
|
Answer» Correct Answer - A |
|
| 148. |
The correct curve between the stopping potential `(V)` and intensity of incident light `(I)` isA. B. C. D. |
|
Answer» Correct Answer - B |
|
| 149. |
Light of frequency `v` is incident on a certain photoelectric substance with threshold frequency `v`. The work function for the substance isA. hvB. hv0C. `h(v-v_(0))`D. `h(v+v_(0))` |
|
Answer» Correct Answer - B |
|
| 150. |
The threshold wavelength for photoelectric effect of a metal is 6500 Å. The work function of the metal is approximatelyA. 2 eVB. 1 eVC. 0.1 eVD. 3 eV |
|
Answer» Correct Answer - A |
|