181 + Interview Questions in ELECTRON IN GENERAL AWARENESS Page 1 InterviewSolution

1.	The wavelength of X-rays isA. 2000 ÅB. 2 ÅC. 1 mmD. 1 cm
Answer» Correct Answer - B

Discussion

2.	The energy of a photon is `E = hv` and the momentum of photon `p = (h)/(lambda)` , then the velocity of photon will beA. `E//p`B. `Ep`C. `((E)/(p))^(2)`D. `3 xx 10^(8) m//s`
Answer» Correct Answer - A

Discussion

3.	The momentum of a photon of energy `hv` will beA. `hv`B. `hv//c`C. `hvc`D. `h//v`
Answer» Correct Answer - B

Discussion

4.	If mean wavelength of light radiated by `100 W` lamp is `5000 Å` , then number of photons radiated per second areA. `3 xx 10^(23)`B. `2.5 xx 10^(22)`C. `2.5 xx 10^(20)`D. `5 xx 10^(17)`
Answer» Correct Answer - C

Discussion

5.	The figure shows different graphs between stopping potential `(V_(0))` and frequency `(v)` for photosensitive surface of cesium , potassium , sodium and lithium. The plots are parallel. Correct ranking of the targets according to their work function greatest forst will be A. (i) gt (ii) gt (iii) gt (iv)B. (i) gt (iii) gt (ii) gt (iv)C. (iv) gt (iii) gt (ii) lt (i)D. (i) = (iii) gt (ii) = (iv)
Answer» Correct Answer - C

Discussion

6.	The energy that should be added to an electron to reduce its de - Broglie wavelength from one `nm to 0.5 nm` isA. four times the initial energyB. equal to the initial energyC. twice the initial energyD. thrice the initial energy
Answer» Correct Answer - D

Discussion

7.	Energy of an quanta of frequency `10^(15) Hz` and `h = 6.6 xx 10^(-34) J - sec` will beA. `6.6 xx 10^(-19)J`B. `6.6 xx 10^(-12) J`C. `6.6 xx 10^(-49) J`D. `6.6 xx 10^(-41) J`
Answer» Correct Answer - A

Discussion

8.	When X rays pass through a strong uniform magnetic field. Then theyA. Do not get deflected at allB. Get deflected in the direction of the fieldC. Get deflected in the direction opposite to the fieldD. Get deflected in the direction perpendicular to the field
Answer» Correct Answer - A

Discussion

9.	If `lamda=10 Å` law for X-rays isA. Infra-redB. MicrowaveC. Ultra-violetD. X-rays
Answer» Correct Answer - D

Discussion

10.	X-rays of `lamda = 1Å` have frequencyA. `3 xx 10^(8) Hz`B. `3 xx 10^(18) Hz`C. `3 xx 10^(10) Hz`D. `3 xx 10^(15) Hz`
Answer» Correct Answer - B

Discussion

11.	The dependence of the short wavelength limit `lamda_(min)` on the accelerating potential `V` is represented by the curve of figure A. AB. BC. CD. None of these
Answer» Correct Answer - A

Discussion

12.	The largest distance between the interatomic planes of crystal is `10^(-7) cm`. The upper limit for the wavelength of `X` - rays which can be usefully studied with this crystal isA. 1 ÅB. 2 ÅC. 10 ÅD. 20 Å
Answer» Correct Answer - D

Discussion

13.	X-rays can be used to study crystal structure, if the wavelength lies in the rangeA. 2 Å to 0.1 ÅB. 10 Å to 5 ÅC. 50 Å to 10 ÅD. 100 Å to 50 Å
Answer» Correct Answer - A

Discussion

14.	Assertiion : `X` - rays are used for studying the structure of crystals. Reason : The distance between the atoms of crystals is of the order of wavelength of `X` - rays.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

Discussion

15.	The structure of solid crystals is investigated by usingA. Cosmic raysB. X-raysC. Infrared radiationsD. `gamma-`rays
Answer» Correct Answer - B

Discussion

16.	For the structural analysis of crystals, X-rays are used becauseA. X - rays have wavelength of the order of interatomic spacingB. X - rays are highly penetrating radiationsC. Wavelength iof X-rays is of the order of nuclear sizeD. X-rays are coherent radiation
Answer» Correct Answer - A

Discussion

17.	Quantam nature of light is explained by which of the following phenomenonA. Huygen wave theoryB. Photoelectric effectC. Maxwell electromagnetic theoryD. de-Broglie theory
Answer» Correct Answer - B

Discussion

18.	Photoelectric effect was successfully explained first byA. PlanckB. HallwashC. HertzD. Einstein
Answer» Correct Answer - D

Discussion

19.	The threshold wavelength for photoelectric emission for a material is `5200 A^(@)`. Will the photoelectrons be emitted when this material is illuminated with monochromatic radiation from 1 watt ultra violet lamp?A. 50 watt infrared lampB. Both (c) and (d)C. 50 watt ultraviolet lampD. 1 watt untraviolet lamp
Answer» Correct Answer - D

Discussion

20.	Light of wavelength `2475 Å` is incident on barium. Photoelectrons emitted describe a circle of radius `100 cm` by a magnetic field of flux density `(1)/(sqrt(17)) xx 10^(-5) Tesla`. Work function of the barium is (Given `(e )/(m) = 1.7 xx 10^(11)`) A. 1.8 eVB. 2.1 eVC. 4.5 eVD. 3.3 eV
Answer» Correct Answer - C

Discussion

21.	When light of wavelength `300 nm` (nanometre) falls on a photoelectric emitter , however light of `600 nm` wavelength is sufficient for creating photoemission . What is the ratio of the work functions of the two emitters ?A. `1:2`B. `2:1`C. `4:1`D. `1:4`
Answer» Correct Answer - B

Discussion

22.	A beam of light of wavelength `lambda` and with illumination `L` falls on a clean surface of sodium . If `N` photoelectrons are emitted each with kinetic energy `E` , thenA. `N prop L and E prop L`B. `N prop L and E prop (1)/(lamda)`C. `N prop lamda and E prop L`D. `N prop (1)/(lamda) and E prop (1)/(L)`
Answer» Correct Answer - B

Discussion

23.	Which of the following wavelength falls in X - ray regionA. 10000 ÅB. 1000 ÅC. 1 ÅD. 10 Å
Answer» Correct Answer - C

Discussion

24.	de - Broglie wavelength of a body of mass `1 kg` moving with velocity of `2000 m//s` isA. `3.32 xx 10 Å`B. `1.5 xx 10 Å`C. `0.55 xx 10 Å`D. None of these
Answer» Correct Answer - A

Discussion

25.	When subjected to a transverse electric field, cathode rays moveA. Down the potential gradientB. Up to potential gradientC. Along a hyperbolic pathD. Along a circular path
Answer» Correct Answer - B

Discussion

26.	The charge on electron was discovered byA. J.J. ThomsonB. Neil BohrC. MillikanD. Chadwick
Answer» Correct Answer - C

Discussion

27.	When the speed of electrons increases, then the value of its specific chargeA. IncreasesB. DecreasesC. Remails unchangedD. Increases upto some velocity and then begins to decrease
Answer» Correct Answer - B

Discussion

28.	The specific charge of an electron isA. `1.6 xx 10^(-19)` coulombB. `4.8 xx 10^(-10)` statcoulombC. `1.76 xx 10^(11)` coulomb/kgD. `1.76 xx 10^(-11)` coulomb/kg
Answer» Correct Answer - C

Discussion

29.	Positive rays was discovered byA. ThomsonB. GolstemC. W. CrookesD. Rutherford
Answer» Correct Answer - A

Discussion

30.	Positive rays consist ofA. ElectronsB. NeutronsC. Positive ionsD. Electro magnetic waves
Answer» Correct Answer - C

Discussion

31.	Stopping potential for photoelectronsA. Does not depend on the frequency of the incident lightB. Does not depend upon the nature of the cathode materialC. Depends on both the frequency of the incident light and nature of the cathode materialD. Depends upon the intensity of the incident light
Answer» Correct Answer - C

Discussion

32.	Assertion : When the speed of an electron increases its specific charge decreases. Reason : Specific charge is the ratio of the change to mass.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

Discussion

33.	Assertion : The specific charge of positive rays is not constant. Reason : The mass of ions varies with speed.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

Discussion

34.	The current conduction in a discharged tube is due toA. Electrons onlyB. `+ve` ions and electronsC. `-ve` ions and electronsD. `+ve` ions, `-ve` ions and electrons
Answer» Correct Answer - D

Discussion

35.	An electron is accelerated through a p.d of 25.5 volt. The velocity acquired by it is (in ms)A. `4 xx 10^(6)`B. `4 xx 10^(4)`C. `10^(6)`D. Zero
Answer» Correct Answer - A

Discussion

36.	An `alpha`-particle is accelerated through a.p.d of `10^(6)` volt the `K.E.` of particle will beA. 8 MeVB. 4 MeVC. 2 MeVD. 1 MeV
Answer» Correct Answer - C

Discussion

37.	An electron initially at rest, is accelerated through a potential difference of `200` volt, so that it acquires a velocity `8.4 xx 10^(6)m//s`. The value of `e//m` of elctronA. `2.76 xx 10^(12) C//kg`B. `1.76 xx 10^(11) C//kg`C. `0.76 xx 10^(12) C//kg`D. None of these
Answer» Correct Answer - B

Discussion

38.	A photosensitive metallic surface has work funtion `hv_(0)`. If photons of energy `2hv_(0)` fall on this surface the electrons come out with a maximum velocity of `4xx10^(6) m//s`. When the photon energy is increases to `5hv_(0)` then maximum velocity of photo electron will beA. `2xx10^(6)` m/sB. `2xx10^(7)` m/sC. `8xx10^(5)` m/sD. `8xx10^(6)` m/s
Answer» Correct Answer - D

Discussion

39.	If particles are moving with same velocity , then maximum de - Broglie wavelength will be forA. NeutronB. ProtonC. `beta-`particleD. `alpha-`particles
Answer» Correct Answer - C

Discussion

40.	Frequency of photon having energy 66 eV isA. `8 xx 10^(-15) Hz`B. `12 xx 10^(-15) Hz`C. `16 xx 10^(15) Hz`D. None of these
Answer» Correct Answer - C

Discussion

41.	The approximate wavelength of a photon of energy `2.48 eV` isA. 500 ÅB. 5000 ÅC. 2000 ÅD. 1000 Å
Answer» Correct Answer - B

Discussion

42.	The energy of a photon of light of wavelength 66 eV isA. `4.4 xx 10^(-19)`B. `2.5 xx 10^(-19) J`C. `1.25 xx 10^(-17) J`D. `2.5 xx 10^(-17) J`
Answer» Correct Answer - A

Discussion

43.	Radiation pressure on any surface is :A. is dependent on wavelength of the light usedB. is dependent on nature of surface and intensity of light usedC. is dependent on frequency and nature of surfaceD. depends on the nature of source from which light is coming
Answer» Correct Answer - B

Discussion

44.	Which is not true with respect to the cathode rays ?A. A stream of electronsB. Charged particlesC. Move with speed same as that of lightD. Can be deflected by magnetic fields
Answer» Correct Answer - C

Discussion

45.	From the figure describing photoelectric effect we may infer correctly that A. Na and Al both have the same threshold frequencyB. Maximum kinetic energy for both the metals depens lineraly o the frequencyC. The stopping potentials are different for Na and Al for the same change in frequencyD. Al is a better photosentive material than Na
Answer» Correct Answer - B

Discussion

46.	In a parabola spectrograph, the velocities of four positive ions P,Q,R and S are `v_(1),v_(2),v_(3)` and `v_(4)` respectively A. `v_(1) gtv_(2)gtv_(3)gtv_(4)`B. `v_(1) lt v_(2) lt v_(3) lt v_(4)`C. `v_(1)=v_(2)=v_(3)=v_(4)`D. `v_(1) lt lt v_(2) gt v_(3) lt v_(4)`
Answer» Correct Answer - A

Discussion

47.	The momentum of a photon in an X - ray beam of `10^(-10) metre` wavelength isA. `1.5 xx 10^(-23) kg-m//sec`B. `6.6 xx 10^(-24) kg-m//sec`C. `6.6 xx 10^(-44) kg-m//sec`D. `2.2 xx 10^(-52) kg-m//sec`
Answer» Correct Answer - B

Discussion

48.	An electron is moving with constant velocity along x-axis. If a uniform electric field is applied along y-axis, then its path in the x-y plane will beA. A straight lineB. A circleC. A parabolaD. An ellipse
Answer» Correct Answer - C

Discussion

49.	When electron beam passes through an electric field,they gain kinetic energy. If the same beam passes through magnetic field, thenA. Their energy increasesB. Their momentum increasesC. Their potential energy increasesD. Energy and momentum both remains unchanged
Answer» Correct Answer - D

Discussion

50.	Which of the following has the least value of `(q)/(m)`?A. ElectronB. ProtonC. `alpha-`particlesD. `beta-` partices
Answer» Correct Answer - C

Discussion

Explore topic-wise InterviewSolutions in .

The wavelength of X-rays isA. 2000 ÅB. 2 ÅC. 1 mmD. 1 cm

The energy of a photon is `E = hv` and the momentum of photon `p = (h)/(lambda)` , then the velocity of photon will beA. `E//p`B. `Ep`C. `((E)/(p))^(2)`D. `3 xx 10^(8) m//s`

The momentum of a photon of energy `hv` will beA. `hv`B. `hv//c`C. `hvc`D. `h//v`

If mean wavelength of light radiated by `100 W` lamp is `5000 Å` , then number of photons radiated per second areA. `3 xx 10^(23)`B. `2.5 xx 10^(22)`C. `2.5 xx 10^(20)`D. `5 xx 10^(17)`

The energy that should be added to an electron to reduce its de - Broglie wavelength from one `nm to 0.5 nm` isA. four times the initial energyB. equal to the initial energyC. twice the initial energyD. thrice the initial energy

Energy of an quanta of frequency `10^(15) Hz` and `h = 6.6 xx 10^(-34) J - sec` will beA. `6.6 xx 10^(-19)J`B. `6.6 xx 10^(-12) J`C. `6.6 xx 10^(-49) J`D. `6.6 xx 10^(-41) J`

When X rays pass through a strong uniform magnetic field. Then theyA. Do not get deflected at allB. Get deflected in the direction of the fieldC. Get deflected in the direction opposite to the fieldD. Get deflected in the direction perpendicular to the field

If `lamda=10 Å` law for X-rays isA. Infra-redB. MicrowaveC. Ultra-violetD. X-rays

X-rays of `lamda = 1Å` have frequencyA. `3 xx 10^(8) Hz`B. `3 xx 10^(18) Hz`C. `3 xx 10^(10) Hz`D. `3 xx 10^(15) Hz`

The dependence of the short wavelength limit `lamda_(min)` on the accelerating potential `V` is represented by the curve of figure A. AB. BC. CD. None of these

The largest distance between the interatomic planes of crystal is `10^(-7) cm`. The upper limit for the wavelength of `X` - rays which can be usefully studied with this crystal isA. 1 ÅB. 2 ÅC. 10 ÅD. 20 Å

X-rays can be used to study crystal structure, if the wavelength lies in the rangeA. 2 Å to 0.1 ÅB. 10 Å to 5 ÅC. 50 Å to 10 ÅD. 100 Å to 50 Å

The structure of solid crystals is investigated by usingA. Cosmic raysB. X-raysC. Infrared radiationsD. `gamma-`rays

For the structural analysis of crystals, X-rays are used becauseA. X - rays have wavelength of the order of interatomic spacingB. X - rays are highly penetrating radiationsC. Wavelength iof X-rays is of the order of nuclear sizeD. X-rays are coherent radiation

Quantam nature of light is explained by which of the following phenomenonA. Huygen wave theoryB. Photoelectric effectC. Maxwell electromagnetic theoryD. de-Broglie theory

Photoelectric effect was successfully explained first byA. PlanckB. HallwashC. HertzD. Einstein

Light of wavelength `2475 Å` is incident on barium. Photoelectrons emitted describe a circle of radius `100 cm` by a magnetic field of flux density `(1)/(sqrt(17)) xx 10^(-5) Tesla`. Work function of the barium is (Given `(e )/(m) = 1.7 xx 10^(11)`) A. 1.8 eVB. 2.1 eVC. 4.5 eVD. 3.3 eV

When light of wavelength `300 nm` (nanometre) falls on a photoelectric emitter , however light of `600 nm` wavelength is sufficient for creating photoemission . What is the ratio of the work functions of the two emitters ?A. `1:2`B. `2:1`C. `4:1`D. `1:4`

Which of the following wavelength falls in X - ray regionA. 10000 ÅB. 1000 ÅC. 1 ÅD. 10 Å

de - Broglie wavelength of a body of mass `1 kg` moving with velocity of `2000 m//s` isA. `3.32 xx 10 Å`B. `1.5 xx 10 Å`C. `0.55 xx 10 Å`D. None of these

When subjected to a transverse electric field, cathode rays moveA. Down the potential gradientB. Up to potential gradientC. Along a hyperbolic pathD. Along a circular path

The charge on electron was discovered byA. J.J. ThomsonB. Neil BohrC. MillikanD. Chadwick

When the speed of electrons increases, then the value of its specific chargeA. IncreasesB. DecreasesC. Remails unchangedD. Increases upto some velocity and then begins to decrease

The specific charge of an electron isA. `1.6 xx 10^(-19)` coulombB. `4.8 xx 10^(-10)` statcoulombC. `1.76 xx 10^(11)` coulomb/kgD. `1.76 xx 10^(-11)` coulomb/kg

Positive rays was discovered byA. ThomsonB. GolstemC. W. CrookesD. Rutherford

Positive rays consist ofA. ElectronsB. NeutronsC. Positive ionsD. Electro magnetic waves

Stopping potential for photoelectronsA. Does not depend on the frequency of the incident lightB. Does not depend upon the nature of the cathode materialC. Depends on both the frequency of the incident light and nature of the cathode materialD. Depends upon the intensity of the incident light

The current conduction in a discharged tube is due toA. Electrons onlyB. `+ve` ions and electronsC. `-ve` ions and electronsD. `+ve` ions, `-ve` ions and electrons

An electron is accelerated through a p.d of 25.5 volt. The velocity acquired by it is (in ms)A. `4 xx 10^(6)`B. `4 xx 10^(4)`C. `10^(6)`D. Zero

An `alpha`-particle is accelerated through a.p.d of `10^(6)` volt the `K.E.` of particle will beA. 8 MeVB. 4 MeVC. 2 MeVD. 1 MeV

An electron initially at rest, is accelerated through a potential difference of `200` volt, so that it acquires a velocity `8.4 xx 10^(6)m//s`. The value of `e//m` of elctronA. `2.76 xx 10^(12) C//kg`B. `1.76 xx 10^(11) C//kg`C. `0.76 xx 10^(12) C//kg`D. None of these

If particles are moving with same velocity , then maximum de - Broglie wavelength will be forA. NeutronB. ProtonC. `beta-`particleD. `alpha-`particles

Frequency of photon having energy 66 eV isA. `8 xx 10^(-15) Hz`B. `12 xx 10^(-15) Hz`C. `16 xx 10^(15) Hz`D. None of these

The approximate wavelength of a photon of energy `2.48 eV` isA. 500 ÅB. 5000 ÅC. 2000 ÅD. 1000 Å

The energy of a photon of light of wavelength 66 eV isA. `4.4 xx 10^(-19)`B. `2.5 xx 10^(-19) J`C. `1.25 xx 10^(-17) J`D. `2.5 xx 10^(-17) J`

Radiation pressure on any surface is :A. is dependent on wavelength of the light usedB. is dependent on nature of surface and intensity of light usedC. is dependent on frequency and nature of surfaceD. depends on the nature of source from which light is coming

Which is not true with respect to the cathode rays ?A. A stream of electronsB. Charged particlesC. Move with speed same as that of lightD. Can be deflected by magnetic fields

In a parabola spectrograph, the velocities of four positive ions P,Q,R and S are `v_(1),v_(2),v_(3)` and `v_(4)` respectively A. `v_(1) gtv_(2)gtv_(3)gtv_(4)`B. `v_(1) lt v_(2) lt v_(3) lt v_(4)`C. `v_(1)=v_(2)=v_(3)=v_(4)`D. `v_(1) lt lt v_(2) gt v_(3) lt v_(4)`

The momentum of a photon in an X - ray beam of `10^(-10) metre` wavelength isA. `1.5 xx 10^(-23) kg-m//sec`B. `6.6 xx 10^(-24) kg-m//sec`C. `6.6 xx 10^(-44) kg-m//sec`D. `2.2 xx 10^(-52) kg-m//sec`

An electron is moving with constant velocity along x-axis. If a uniform electric field is applied along y-axis, then its path in the x-y plane will beA. A straight lineB. A circleC. A parabolaD. An ellipse

When electron beam passes through an electric field,they gain kinetic energy. If the same beam passes through magnetic field, thenA. Their energy increasesB. Their momentum increasesC. Their potential energy increasesD. Energy and momentum both remains unchanged

Which of the following has the least value of `(q)/(m)`?A. ElectronB. ProtonC. `alpha-`particlesD. `beta-` partices