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# OAU PHY 205 Class Notes

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This PDF is the class notes for OAU PHY 205 during the 2022/2023 session.

It encompasses topics ranging from Blackbody radiation, electrons and quanta, thermionic emissions, to photoelectric emissions, Compton effect, and uniform density.

I added from different people’s class notes, jotting from lecturers’ explanations, and added the slides/PDFs the lecturers dropped and orderly compiled them together, just for you.😉

Also, note that this file contains PHY 205 Past Question at the end for you to practice.

Note credit;

Rotimi, Raphael, and Com4forth (in OAU CHM department)

I will continually update this file as we proceed through the classes. Thank you.

Please, note that there may be some mistakes in the notes, because of some form of parallax error.😂 Please, kindly confirm and cross-check.

I hope the note helps.

# PHY 203 Quiz For OAU

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Created by Oluwaferanmi Akinyele

PHY 203 Quiz

These are likely questions for our test based on our class notes, few questions our lecturers asked in class, examples in the notes and some online questions.

This quiz consists of 95 questions covering all the topics we have been taught in PHY 203 till present. I hope we all find it helpful.

You have 50 mins for this quiz.

Contributors: Zainab, Verah & Lammylex (CHM department)

and Shukroh, Great Blakky and Ebun (PHY department)

Goodluck!❤️

1 / 95

1. Extrinsic semiconductors have more current conducting capacity than intrinsic semiconductors

2 / 95

2. An Inductor tend to smooth sudden change in ……………..

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3. Which of the statements about PN junction is true

I. A PN junction presents a high resistance if forward biased.

II. A PN junction presents a high resistance if reversed biased.

III A PN junction presents a low resistance if forward biased.

IV. A PN junction presents a low resistance if reversed biased.

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4. A Thevenin’s equivalent circuit contains an equivalent source Vth in parallel with an equivalent resistor Rth

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5. A node is a collection point for two or more banches

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6. An ammeter also detects the direction of the flow of current

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7. A component that allows the flow of current in only one direction is called ……….

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8. If a circuit has the following parameters Vcc =20V, Rs +Rm = 9.3KΩ, Vbe = 0.7, Im =1mA, and Β = 100. Calculate the meter current when E =10V and the voltmeter input r with or without the transistor.

9 / 95

9. The loss due to ohmic resistance of the transformer windings

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10. A multiplier measures ………………, ………………….. and …………………

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11. Consider the following statements and choose only correct answers

I. The resistivity of a semiconductor is less than that of an insulator and more than a conductor

II. As temperature increases, the conductivity of semiconductors decreases

III. We can consider a semiconductor as a resistance material

IV. Semiconductors have a negative temperature coefficient of resistance

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12. The majority carriers in an n-type semiconductor is ?

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13. Select the correct options only

I. Pentavalent impurities provide large number of free electrons to the semiconductor.

II. Trivalent impurities provide large number of free electrons to the semiconductor.

III. Trivalent impurities provide large number of holes to the semiconductor.

IV. Pentavalent impurities provide large number of holes to the semiconductor.

14 / 95

14. In checking for continuity of circuit which on these is used

15 / 95

15. The emf that gets induced in the secondary winding according to Faraday’s law of electromagnetic induction is called?

16 / 95

16. A capacitor and an Inductor in an AC circuit is referred to as

17 / 95

17. What type of bonds exist in semiconductors

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18. The resistivity of a semiconductor is ………. that of an insulator, and …………that of conductors

19 / 95

19. A transformer consists of two inductive coils namely;

20 / 95

20. The transistor is a current __________ device.

21 / 95

21. Any transistor designed must operate in the ________ region of the characteristic curve

22 / 95

22. A meter is protected in the case of accidental workload by connecting …………… in ………….. with a voltmeter

23 / 95

23. The loss due to the reversal of magnetization in the transformer core is known as

24 / 95

24. A 6600/550V, 25KVA transformer has iron losses of 350W and its 1º and 2° winding resistances are 14.5 and 0.1Ω respectively. Determine the full load efficiency at a power factor of unity.

25 / 95

25. To convert a multiplier to an ammeter, a ………. resistance is connected in ……………… with a galvanometer

26 / 95

26. A capacitor stores charge and hence, electric energy

27 / 95

27. In a RC circuit, voltage across the resistor ………………. exponentially with time

28 / 95

28. The potential barrier of a P-N junction depends on which of the following except

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29. Copper loss is usually larger than other losses

30 / 95

30. Which of this must be connected to multimeter to be able to measure AC voltages?

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31.

How many branches, nodes, loop and mesh do we have here?

32 / 95

32. Which of the following is true about the effect of temperature on semiconductors

I. At absolute zero, there are no free electrons.

II. Above absolute zero, bonds break and electrons move under the influence of the applied electric field.

III. The semiconductor has its highest conductivity at absolute zero

IV. The semiconductor behaves as a perfect insulator at absolute zero

33 / 95

33. Which of the following is/are correct?

I. Bipolar junction transistors control the current by varying the number of charge carriers

II. Voltage between 2 terminals are indicated by repeated letters

III. The emitter is lightly doped to reduce junction capacitance

IV. The emitter-base junction is forward biased

34 / 95

34. A perfect amplifier has all of the following properties except:

35 / 95

35. Which of the following is true about transformers?

I. Open circuit test are done with a load on the transformer.

II. Copper loss is due to the ohmic resistance of the transformer windings.

III. Open circuit test is done to determine the ‘no load loss’ of the transformer.

IV. A transformer is electrically linked.

36 / 95

36. Coils are …………… separated, but ……………. linked together

37 / 95

37. In pure inductors, current ……… the voltage by ……

38 / 95

38. The e–h+ pair can also be called ____

39 / 95

39. Circuit elements are connected in parallel when a common ……………. is applied to each elements

40 / 95

40. Which of the following is/are true

I. Reverse biasing prevents the flow of charge carriers across the junction.

II. Forward biasing is created when the positive terminal is connected to the n-type part of the PN junction.

III. In practice, when we apply reverse biasing to a PN junction, all the charge carriers stops to flow.

41 / 95

41. In electronics, _____ refers to the use of DC voltage to establish certain operating conditions for an electronic device.

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42. In a transformer, most flux which get linked to the secondary winding is called?

43 / 95

43. A material that releases an electron from the valence band into the conduction band when a photon of light is incident on it is a ___________

44 / 95

44. A inductor stores energy in its _________

45 / 95

45. A capacitor C and an Inductor L store…………….. and ……………….. respectively

46 / 95

46. The core in a transformer provides ?

47 / 95

47. What is known as eddy current loss in a transformer?

48 / 95

48. The separation between conduction band and valence band on the energy level diagram is called ________

49 / 95

49. Calculate Rth, Vth, and I5

50 / 95

50. The voltage signal at the collector is out of phase with the signal at the base by:

51 / 95

51. Which of the following is correct

I. Small changes in V(BE) will produce large current changes in I(C) & I(E)

II. Small changes in V(CE) have little effect on I(B)

III. Small changes in V(CE) will produce large current changes in I(C) & I(E)

I, II, III & IVIV. Small changes in V(BE) will produce large current changes in I(B)

52 / 95

52. Which of the following statements is/are true? I. A multimeter can be used as an ammeter when low resistance is connected in parallel with the galvanometer II. A low sensitive meter will measure Voltage perfectly III. A multimeter cannot be used to determine circuit continuity IV. A multimeter can be used as an voltmeter when high resistance is connected in series with the galvanometer

53 / 95

53. In an RL circuit voltage across the resistor increases exponentially

54 / 95

54. Voltmeter draws …………………… current

55 / 95

55. A p-n junction is also known as

56 / 95

56. A hole can also be described as a _________

57 / 95

57. A transformer only increases the voltage with corresponding increase in current

58 / 95

58. When a small amount of trivalent impurity is added to a pure semi conductor, the semi conductor becomes

59 / 95

59. A emitter-follower circuit has Vcc =12V, Rm = 1KΩ and a 2mA meter. If the amplification factor of the resistor is 80 and Vbe = 0.7. Calculate the suitable r for Rs to give fsd when E= 5V.

60 / 95

60. A galvanometer measures and detects extremely small currents both in ………………… and ………………………

61 / 95

61. On the basis of their use, transformers are classified as

62 / 95

62. …………………. are responsible for the conduction  in a conductor

63 / 95

63. Depletion layer serves as barrier to the movement of free electrons.

64 / 95

64. The process of setting up a current to operate a transistor at a desired point on its characteristic curve is known as __________

65 / 95

65. A semiconductor in an extremely pure form is known as ………….

66 / 95

66. In a multimeter, when the variable resistance and the fixed resistance are connected in series with the battery and galvanometer, the multimeter functions as

67 / 95

67. The Norton’s equivalent circuit contains a Norton equivalent source “I(N)” in parallel with an equivalent resistor R(N)

68 / 95

68. The most versatile circuit configuration for transistors is the

69 / 95

69. The arrangement of atoms in a repetitive manner is known as

70 / 95

70. No electrons can stay in the forbidden gap because

71 / 95

71. In a semiconductor, as temperature increases, conductivity ………………

72 / 95

72. when the sensitivity of a meter is high, it means the meter has ………….

73 / 95

73. A laminated steel core that has high silicon content provides

74 / 95

74. Inductors are very common in high-frequency circuit

75 / 95

75. Calculate the current flowing in the circuit

76 / 95

76. Which of the following transformers has a high rating?

77 / 95

77. Calculate Ia, Ib and Ic

78 / 95

78. A mesh is any closed path in a circuit which does not enclose any other closed path inside it

79 / 95

79. Calculate the equivalent resistance

80 / 95

80. A variable resistor in an electric circuit is for ……………

81 / 95

82 / 95

82. The principle behind the working of a transformer is _________

83 / 95

83. What is the number of branches, nodes, loops, and meshes?

84 / 95

84. p-type and n-type semiconductor join together to form a …………….. known as …………….

85 / 95

85. AC Current and Voltage may vary with time. True or False?

86 / 95

86. ________ converts alternating currents into direct currents

87 / 95

87. The collector current is determined by the _________

88 / 95

88. Circuit elements connected in series have common …………….. passing through each element

89 / 95

89. The transistor is a three-terminal device that we can use to form a _____________ circuit

90 / 95

90. A resistor is regarded as a circuit element which puts energy into a circuit

91 / 95

91. Why is a laminated steel core used in a transformer instead of a solid core?

92 / 95

92. Which of these will result in forward biasing

I. when certain dc voltage is applied to the junction in such a direction that it cancels the potential barrier thus permitting the flow of current

II. Connecting the negative terminal of the battery to the p-type and positive terminal to the n-type

III. Connecting the positive terminal of the battery to the p-type and negative terminal to the n-type

IV. when certain dc voltage is applied to the junction in such a direction that the potential barrier is increased

93 / 95

93. What are the examples of passive elements?

94 / 95

94. Inductors smoothen sharp sudden changes in ……….

95 / 95

95. Which of this is true

The average score is 53%

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# Quiz for CSC 201

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You have 30 mins for this quiz

Time up!

Created by Oluwaferanmi Akinyele

CSC 201

Preparatory Quiz for CSC 201 Test 2022/2023. This quiz contains 40 multiple choice questions.

The questions are compiled by Physics department gurus;

Ebun (Class rep)

Levi

Oluwaferanmi

Great

and Blakky

1 / 40

The following are program elements except

2 / 40

Which keyword is used to call a function in Python language?

3 / 40

What is the maximum possible length of an identifier in Python?

4 / 40

Which one of the following is the use of function in python?

5 / 40

Which of the following is an invalid variable?

6 / 40

Python was created in what year

7 / 40

Which of the following is true for variable names in Python?

8 / 40

What are the two main types of functions in Python?

9 / 40

What will be the value of X in the following Python expression?

“`X = 2+9*((3*12)-8)/10“`

10 / 40

What is the value of the following expression?

“`float(22//3+3/3)“`

11 / 40

Application software includes the following except

12 / 40

Which of the following variable naming is correct

13 / 40

The correct sequence of the history of modern era is

14 / 40

Who developed Python Programming Language?

15 / 40

What are the values of the following Python expressions?

“` 2**(3**2)“`

“` (2**3)**2“`

“` 2**3**2“`

16 / 40

Which of the following functions is a built-in function in python?

17 / 40

Which of the following is used to define a block of code in Python language?

18 / 40

Which type of Programming does Python support?

19 / 40

The expression

“`2**2**3“` is equal to “`(2**2)**3“`

20 / 40

The following is true about python except

21 / 40

Is Python case sensitive when dealing with identifiers?

22 / 40

‘Bit’ stands for

23 / 40

Operating Systems includes the following except

24 / 40

What is the average value of the following Python code snippet?

25 / 40

What is the order of precedence in python?

26 / 40

The ______ is the brain of the computer that performs simple arithmetic & logical operations

27 / 40

Which among the following list of operators has the highest precedence?

“` +, -, **, %, /, <<, >>, |“`

28 / 40

A computer software comprises of ___________ software & ___________ software

29 / 40

Machines developed in transistor era include the following except

30 / 40

Which of the following is the correct extension of the Python file?

31 / 40

A ________ is a sequence of instructions telling the computer what to do.

32 / 40

Which of the following is an invalid statement?

33 / 40

The outcome of a programming activity is a _________

34 / 40

What will be the output of the following Python expression?

“`round(4.576)“`

35 / 40

The following are high-level languages except

36 / 40

Machines developed in mechanical era include the following except

37 / 40

The following are python reserved words excerpt

38 / 40

Is Python code compiled or interpreted?

39 / 40

In flow charts, a terminal is represented with what shape

40 / 40

Which of the following character is used to give single-line comments in Python?

The average score is 66%

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# PHY 205 Quiz

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OAU PHY 205 Quiz

PHY 205

1 / 34

1. Electrons, being fermions, adhere to which principle that prohibits two electrons from occupying the same quantum state?

2 / 34

2. What is the electric charge of a positron?

3 / 34

3. What term is used to describe the lowest energy state that an electron can occupy within an atom?

4 / 34

4. Which branch of physics is concerned with the quantization of energy and its effects on the interaction of matter and energy?

5 / 34

5. What type of process is represented by this equation e† + e¯ → ϒ + ϒ

6 / 34

6. Which of the following is not quantized?

7 / 34

7. Wavelength is inversely proportional to an object’s mass

8 / 34

8. Which field properties does an electron exhibit due to its charge and motion?

9 / 34

9. Electrons absorbs energy in form of photons as they are accelerated

10 / 34

10. Which of the following statements about electrons within an atom is true?

11 / 34

11. What is the relative mass of an electron compared to a proton?

12 / 34

12. What is the intrinsic angular momentum (spin) value of an electron?

13 / 34

13. Which of the following statements is TRUE?

14 / 34

1. If the dimensions of the nucleus are small enough, what can happen to alpha particles passing very near the nucleus in Rutherford's model?

15 / 34

2. How are the electrons distributed in Thomson's model?

16 / 34

3. What are electromagnetic waves?

17 / 34

4. What is the significance of alpha particle scattering experiments in Rutherford's model?

18 / 34

5. What is the primary reason for the scattering of alpha particles in Rutherford's model?

19 / 34

6. Arrange the following types of electromagnetic radiation in order of increasing frequency:

20 / 34

7. Arrange the following types of electromagnetic radiation in order of increasing wavelength

21 / 34

8. In Thomson's model, where are the negatively charged electrons located?

22 / 34

9. How do the oscillations of the electrical and magnetic components in electromagnetic waves relate to the direction of propagation?

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10. In electromagnetic waves, how do the electrical and magnetic components oscillate?

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11. In quantum mechanics, what role does a photon play in the electromagnetic field?

25 / 34

12. What is a photon?

26 / 34

13. In Rutherford's model, where is the positive charge concentrated?

27 / 34

14. According to quantum mechanics, what is the alternate view of electromagnetic radiation (EMR)?

28 / 34

1. What happens when a metal wire is heated in a vacuum during thermionic emission?

29 / 34

2. What is thermionic emission?

30 / 34

3. In what devices are cathode ray tubes commonly used?

31 / 34

4. High beam of cathode ray in vacuum tube can be steered and manipulated by

32 / 34

5. What type of radiation can be produced using cathode ray tubes?

33 / 34

6. In Thompson’s experiment, a a beam of electron travelling at 6.8 x 10^7m/s is bent into a circular path of radius 4cm in the magnetic of induction 10^-2 W/m2. Find the specific charge to mass (e/m)

34 / 34

7. Why is it necessary for the tube to be in a vacuum during thermionic emission?

The average score is 66%

0%

# OAU PHY 203 Class Notes

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This PDF is the class notes for OAU  PHY 203 during the 2022/2023 session.

It encompasses topics ranging from circuit theory and network theorems to Thevenin’s and Norton’s theorems, progressing further into AC circuits, transformers, physics of active devices, semiconductors, and more.

I will continually update this file as we proceed through the classes. Thank you.

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