Modern Physics & Electronics - Quanta: BS/MSc Physics Books

1: If energy of photon is , it is equivalent to mass m = · · ·

a. $\frac{E}{c^2}$

b. $\frac{2E}{c^2}$

c. $\frac{h\nu}{c}$

d. All of these

2: Black body can be made by a · · · within a solid body

a. Cavity

b. Hollow cavity

c. Material

d. Cylinder

3: The magnitude of plank’s constant is · · ·

a. $6.625\times{10}^{-34}Js$

b. $6.625\times{10}^{-31}Js$

c. $6.625\times{10}^{-19}Js$

d. $6.625\times{10}^{-27}Js$

4: In photoelectric effect, the maximum kinetic energy is zero if · · ·

a. $h\nu\ \le\ \phi$

b. $h\nu\ \geq\ \phi$

c. $h\nu\ \ll\ \phi$

d. $h\nu\ \gg\ \phi$

5: The maximum speed of electrons emitted by incident light on metal surface depends only on · · · of incident light

a. Intensity

b. Frequency

c. Energy

d. All of these

6: A · · · can be used in burglar alarm and opening the door automatically

a. Cavity

b. Line spectrum

c. Photocell

d. None of these

7: At low temperature, the body generally emits the radiations of · · · wavelength

a. Short

b. Long

c. a and b

d. None of these

8: The radiations emitted by human body lies in.

a. Ultraviolet

b. Gamma

c. Infrared

d. All of these

9: In a photocell, cesium coated oxide silver emits electron for

a. Ultraviolet light

b. Gamma light

c. Infrared light

d. All of these

10: · · · has strongest photons

a. Alpha rays

b. Beta rays

c. Gamma rays

d. All of these

11: If α-particle and deuteron move with velocity and , the ratio of their de Broglie

wavelengths will be · · ·

a. $1:\sqrt2$

b. 1:1

c. 2∶1

d. $\sqrt2:\ 1$

12: What is the velocity of a particle of mass m and de-Broglie wavelength

a. $h/m\lambda$

b. $2h/m\lambda$

c. $h\lambda/m$

d. $\left(\frac{2hc}{m\lambda}\right)^\frac{1}{2}$

13: The Davisson-Germer experiment demonstrated the

a. particle nature of electron

b. wave nature of electron

c. wave nature of photon

d. particle nature of photon

14: Energy of α particles having de Broglie wavelength · · ·

a. $1280\ MeV$

b. $1200\ eV$

c. $1280\ eV$

d. $1200\ GeV$

15: Uncertainty principle is applicable to

a. microscopic particles

b. Macroscopic particles

c. Gases

d. None

16: A proton, a neutron, an electron and an α-particle have same energy. Then their de Broglie wavelengths compare as

a. $\lambda_p\ =\ \lambda_n\ >\ \lambda_e\ >\ \lambda_\alpha$

b. $\lambda_\alpha\ <\ \lambda_p\ =\ \lambda_n\ >\ \lambda_e$

c. $\lambda_e\ <\ \lambda_p\ =\ \lambda_n\ >\ \lambda_\alpha$

d. $\lambda_e\ =\ \lambda_p\ =\ \lambda_n\ =\ \lambda_\alpha$

17: For a given kinetic energy, which of the following has smallest de Broglie wavelength?

a. Electron

b. Proton

c. Deuteron

d. α particles

18: A Proton and an α-particle have the same de Broglie wavelength. What is same for both of them?

a. Mass

b. Momentum

c. Frequency

d. Energy

19: The phenomenon of photoelectric emission was discovered in 1887 by

a. Heinrich Hertz

b. Albert Einstein

c. Wilhelm Hallwachs

d. Philipp Lenard

20: Which of the following shows particle nature of light?

a. Refraction

b. Interference

c. Photoelectric effect

d. Polarization

21: In our normal life, we deal with big objects, whose velocity are small in comparison with

a. Velocity of light

b. Velocity of earth

c. Velocity of moon

d. None of these

22: Schrodinger formulation of quantum mechanics, a complex variable quantity ψ (x,y,z)called the …… was introduce to represent the wave associated with a particle in motion

a. Position vector

b. Operator

c. Wave function

d. All of these

23: In quantum mechanics corresponding to every observable, there exists

a. An equation

b. An operator

c. A wave function

d. None of these

24: The potential energy operator is

a. $\hat{V}\ (x)$

b. $i\hbar\frac{\partial}{\partial x}$

c. $\hat{x}$

d. None of these

25: X- component momentum operator is

a. $\hat{V}\ (x)$

b. $i\hbar\frac{\partial}{\partial x}$

c. $\hat{x}$

d. None of these

26: Which of the following statement is false for an electron

a. It is a quantum particle, behaving in some experiments like classical particle, and in some experiment like a classical wave

b. It carries momentum in its motion

c. It carries energy in its motion

d. It has rest energy is zero

27: A beam of quantum particles with kinetic energy 2eV is reflected from potential barrier of small width and original height 3eV . How does the function of particles that are reflected change as the barrier height is reduced to 2.01 eV.

a. It increases

b. It decreases

c. Stays constant

d. Can’t be answered

28: Suppose a tunneling current in an electronic device goes through a potential energy barrier. The tunneling is small because the width of barrier is large and barrier is high. To increases the current most effectively, what should you do

a. Reduce the height of barrier

b. Reduce the width of barrier

c. Either a or b

d. None

29: Quantum mechanics is based on certain postulates, which are sufficient to describe

a. n particle

b. Isolated

c. Closed

d. Single particle

30: The penetration of classically impenetrable barriers by electrons is called

a. Step potential

b. Schrodinger equation

c. Barrier tunneling

d. None

31: In He-Ne laser the lasing action is produced by

a. Ne only

b. He-Ne both

c. Electrons of He

d. Electrons of Ne

32: Excited atoms return to their ground state in

a. ${10}^{-10}\ s$

b. ${10}^{-9}\ s$

c. ${10}^{-8}\ s$

d. ${10}^{-6}\ s$

33: The radiations emitted form hydrogen filled discharge tube show

a. Band spectrum

b. Line spectrum

c. Continuous spectrum

d. Absorption spectrum

34: The meta-stable state for an atom in laser light is

a. ${10}^{-4}\ sec$

b. ${10}^{-5}\ sec$

c. ${10}^{-3}\ sec$

d. ${10}^{-8}\ sec$

35: In hydrogen spectrum which one of the following series lies in the ultraviolet region?

a. Balmer series

b. Pfund series

c. Bracket series

d. Lymann series

36: Hydrogen atom does not emit X- Rays because

a. Its energy levels are too close to each other

b. Its energy levels are too far apart

c. It is too small in size

d. It has a single electron

37: Energy range of X-ray in

a. $10\ eV\ to\ 100\ eV$

b. $100\ eV\ to\ {10}^4\ eV$

c. ∞

d. Zero

38: X-ray are · · ·

a. of unknown nature

b. high energy electrons

c. high energy photons

d. radio isotopes

39: In laser production the state in which more atoms are in the upper state than in the lower one is called

a. Metal stable state

b. Inverted population

c. Normal state

d. All the above

40: X-rays are similar in nature to

a. Cathode rays

b. Positive rays

c. Gamma-rays

d. Beta rays

41: MRI stands for

a. Metallic radiations integrated

b. Metallic resistance imaging

c. Magnetic resonance imaging

d. None of these

42: The proton mass is · · · time larger than electron mass

a. 989

b. 1836

c. 2598

d. 2992

43: SI unit of absorbed dose is

a. Black

b. Gray

c. Ohms

d. RBE

44: Isotopes have same

a. Protons

b. Mass

c. Neutron

d. All of these

45: According to which one of following law the density of atom is uniform

a. J.J. Thomson model

b. Rutherford’s model

c. Bohr’s model

d. All of the above laws contradict the statement

46: Which one of the following radiations possesses maximum penetrating power

a. $X-rays$

b. $\beta-rays$

c. $\gamma-rays$

d. All have the equal penetrating power

47: The bombardment of nitrogen with alpha particles will produce

a. Neutron

b. Proton

c. Electron

d. Positron

48: Radioactive decay obeys which one of the following laws

a. N=N_οe^-λt

b. N=N_οe^λt

c. N=N_οe^-λt/2

d. N_ο= N(1+e^λt)

49: The path of alpha particle is

a. Rectilinear

b. Zig-zag or erratic

c. Curved

d. Elliptical

50: The charge on beta particle is

a. 1

b. −1

c. +2

d. −2

51: In semiconductor like silicon, the unit cell is

a. Simple cube

b. face centered cube

c. body centered cube

d. hexagonal

52: A doped semiconductor has impurity level below the conduction band. The type of material is

a. n-type

b. p-type

c. intrinsic

d. p or n type

53: Electronic distribution of Si atom is

a. 2, 10, 2

b. 2, 7, 5

c. 2, 4, 8

d. 2, 8, 4

54: Semiconductor material has

a. ionic bonding

b. covalent bonding

c. Van der Waal

d. Metallic bonding

55: Electric conduction is a semiconductor takes place due to

a. drift

b. diffusion

c. a and b

d. none of above

56: When electron leaves the n-material to fill holes in p-materials, the process is called

a. doping

b. mixing

c. diffusion

d. depletion

57: A reverse biased ideal diode look like an · · · resistance

a. infinite

b. finite

c. a and b

d. none of these

58: All normal atoms are electrically

a. positively charged

b. negatively charged

c. neutral

d. none of these

59: An ideal diode conducts in forwards direction with · · · Resistance

a. infinite

b. finite

c. zero

d. none of these

60: Free electron moves in · · · band whereas holes move in · · · band

a. conduction, valence

b. valence, conduction

c. filled, empty

d. none of these

MCQ's with Answers

1: If energy of photon is , it is equivalent to mass m = · · ·

2: Black body can be made by a · · · within a solid body

3: The magnitude of plank’s constant is · · ·

4: In photoelectric effect, the maximum kinetic energy is zero if · · ·

5: The maximum speed of electrons emitted by incident light on metal surface depends only on · · · of incident light

6: A · · · can be used in burglar alarm and opening the door automatically

7: At low temperature, the body generally emits the radiations of · · · wavelength

8: The radiations emitted by human body lies in.

9: In a photocell, cesium coated oxide silver emits electron for

10: · · · has strongest photons

11: If α-particle and deuteron move with velocity and , the ratio of their de Broglie

12: What is the velocity of a particle of mass m and de-Broglie wavelength

13: The Davisson-Germer experiment demonstrated the

14: Energy of α particles having de Broglie wavelength · · ·

15: Uncertainty principle is applicable to

16: A proton, a neutron, an electron and an α-particle have same energy. Then their de Broglie wavelengths compare as

17: For a given kinetic energy, which of the following has smallest de Broglie wavelength?

18: A Proton and an α-particle have the same de Broglie wavelength. What is same for both of them?

19: The phenomenon of photoelectric emission was discovered in 1887 by

20: Which of the following shows particle nature of light?

21: In our normal life, we deal with big objects, whose velocity are small in comparison with

22: Schrodinger formulation of quantum mechanics, a complex variable quantity ψ (x,y,z)called the …… was introduce to represent the wave associated with a particle in motion

23: In quantum mechanics corresponding to every observable, there exists

24: The potential energy operator is

25: X- component momentum operator is

26: Which of the following statement is false for an electron

27: A beam of quantum particles with kinetic energy 2eV is reflected from potential barrier of small width and original height 3eV . How does the function of particles that are reflected change as the barrier height is reduced to 2.01 eV.

28: Suppose a tunneling current in an electronic device goes through a potential energy barrier. The tunneling is small because the width of barrier is large and barrier is high. To increases the current most effectively, what should you do

29: Quantum mechanics is based on certain postulates, which are sufficient to describe

30: The penetration of classically impenetrable barriers by electrons is called

31: In He-Ne laser the lasing action is produced by

32: Excited atoms return to their ground state in

33: The radiations emitted form hydrogen filled discharge tube show

34: The meta-stable state for an atom in laser light is

35: In hydrogen spectrum which one of the following series lies in the ultraviolet region?

36: Hydrogen atom does not emit X- Rays because

37: Energy range of X-ray in

38: X-ray are · · ·

39: In laser production the state in which more atoms are in the upper state than in the lower one is called

40: X-rays are similar in nature to

41: MRI stands for

42: The proton mass is · · · time larger than electron mass

43: SI unit of absorbed dose is

44: Isotopes have same

45: According to which one of following law the density of atom is uniform

46: Which one of the following radiations possesses maximum penetrating power

47: The bombardment of nitrogen with alpha particles will produce

48: Radioactive decay obeys which one of the following laws

49: The path of alpha particle is

50: The charge on beta particle is

51: In semiconductor like silicon, the unit cell is

52: A doped semiconductor has impurity level below the conduction band. The type of material is

53: Electronic distribution of Si atom is

54: Semiconductor material has

55: Electric conduction is a semiconductor takes place due to

56: When electron leaves the n-material to fill holes in p-materials, the process is called

57: A reverse biased ideal diode look like an · · · resistance

58: All normal atoms are electrically

59: An ideal diode conducts in forwards direction with · · · Resistance

60: Free electron moves in · · · band whereas holes move in · · · band

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