The electrical and electronic materials are classified into ?
Conducting materials
Dielectric materials
Magnetic materials
All of the above.
Which of the following is dielectric materials ?
Solid
Liquid
Gases
All of the above
The resistivity of high conducting material is _______
Very High
Very Low
High
None of the above
High conducting material is also known as ________
Good conductor
Bad conductor
Semiconductor
None of theabove
Which of the following material have high conductivity ?
Carbon
Aluminium
Silver
Wood
Which of the following are Applications of high conductivity
Wires in cables and insulated conductors
As blades in knife switches
As sockets in receptacles
All of the above
For most materials the resistivity increase with temperature true or false ?
True
False
8. The temperature of silicon decreases then the resistivity also _________
Increase
Decrease
Constant
None of the above
9. Which of the following alloy are high resistivity ?
Manganin
Nichrome
Fechrals
All of the Above
10. Applications of high resistivity materials are
It making standard resistance and resistance boxes
Rheostats and similar control device
Making high temperature element for electric furnaces heating device and loading rheostats
All of the above
11. A phenomenon of exactly zero electrical resistance and explusion of magnetic flux field occuring in certain materials called __________
Conductor
Insulator
Superconductor
None of the above
12. Super conductivity of materials depends on which factors ?
Electron proton interaction
Critical temperature
Electron proton interaction and critical temperature
None of the above
13. Which of the following are superconducting materials ?
Aluminium
Tin
Lead
All of the above
14. Applications of super conducting materials are …….
Used in MRI/NMR machines mass spectrometers.
Used to make digital circuits based on rapid single flux quantum technology.
RF and microwave filter for mobile phone base station.
All of the above.
15. The flow of electric current through any conducting material encounters the opposing force in many respect mechanical friction this opposition force is called
Resistance
Conductance
Capacitance
Inductance
16. Resistors is a _________ components
Active
Passive
Active and Passive
None of the above
17. The passive components which oppose the flow of electric current and has positive temperature coefficient of resistance is called a ___________
Capacitor
Inductor
Resistor
None of the above
18. Registers works on on which source
AC
DC
Both AC and DC
None of the above
19. The smallest unit of resistor is _______
Ohm
Tesla
Weber
Ampere
20. Then largest unit of resistor is _________
Mega ohm
Ohm
Tesla
Ampere
21. Small amount of impurities leads to be a considerable increase in resistivity is called
Alloying
Cold work
Age hardening
None of the above
22. Resistivity of silver is _________
1.629
2.36
112
2.87
23. Resistivity of nichrome is
1.629
2.36
112
2.87
24. Resistivity of Copper is
1.629
2.36
1.68 to 1.77
2.87
25. Resistivity of aluminium is ________ Resistivity of Gold is _______
2.87 & 2.36
0.87 & 0.36
1.87 & 1.36
3.87 & 2.36
26. Which of the following is symbol of Resistor ?
Answer
None of the above
27. The ratio of change in resistance to the actual defined value of resistance for change in temperature is called as
Temperature coefficient of resistance
Tolerance
Specific resistance and resistivity
None of the above
28. Temperature coefficient is denoted by _______
α
b
g
None of the above
29. Types of temperature coefficient of resistance are
Positive
Negative
Zero
All of the above
30. Which of the following materials have positive coefficient of resistance ?
Silver
Copper
Aluminium
All of the above
31. The tolerance means _________
Average
Accuracy
Impurities
None of the above
32. The accuracy to which the values of resistance can be manufactured or selected is called a _________
Tolerance
Temperature coefficient of resistance
Specific resistance
Power Rating
33. The power handling capacity or power rating of a resistor is called _________
Power rating
Tolerance
Wattage
Specific resistance
34. Watage is denoted by _________
W
A
P
S
35. The piece of that material which is 1 m long and of unit cross sectional area is called a __________
Power rating
Specific resistance
Tolerance
Wattage
36. Specific resistance is also known as __________
Wattage
Resistivity
Conductivity
Power rating
37. The maximum amount of heat dissipated by a resistor at maximum specified temperature without damage to resistor is called a __________
Power rating
Wattage
Tolerance
None of the above
38. Mobility of an electron is known as _________
μ=AdE
μ=VdE
μ=dE
μ=E
39. Mobility of an electron is expressed in ________
m/volt-sec
m³/volt-sec
m²/volt-sec
m. volt-sec
40. The energy levels are the _________ diagram.
rectangle
circle
square
Pictorial
41. The liberation of electrons from the surface of any conducting materials usally a metal is called ________
Electron emission
Thermal emission
Secondary emission
Photoelectric emission
42. Work function of a metal is expressed in __________
electron volt
electron current
electron
electron ampere
43. Work function of a metal depends on ?
The properties of the metal
The purity of the metal
The nature of the metal surface
All of the above
44. Types of electron emissions ?
Thermal emission
Secondary emission
Photoelectric emission
All of the above
45. Work function for thermonic emission of copper is ________
4.5 eV
2.3 eV
3.41 eV
1.8 eV
46. Work function for thermonic emission of Nickel is ________
4.5 eV
2.3 eV
3.41 eV
1.8 eV
47. The electron emission from a metal surface which occurs by supplying the thermal energy to the metal is called as __________
Secondary emission
Photoelectric emission
High-field emission
Thermionic emission
48. The commonly used materials for thermometer emotions are ……
Tungsten
Thoriated tungsten
Metallic oxide of Barium and Tungsten
All of the above
49. The electron emission from the surface of a metal which occurs due to the application of strong electric field is _________
Secondary emission
Photoelectric emission
High-field emission
Thermionic emission
50. High field emission is used as …
Mercury arc rectifier
X-ray tube
Both
None of the above
51. When the high velocity electrons strike a material the knock out
electrons from the surface of that material this phenomena is known as
● Secondary emission
● Photoelectric emission
● High-field emission
● Thermionic emission
52. Secondary emission is used in ________
● X-Ray tube
● arc Rectifier
● CRT
● All of the above
53. The electrons emission from the metal surface when illuminated by
light is called __________
● Secondary emission
● Photoelectric emission
● High-field emission
● Thermionic emission
54. The photoelectric materials are…
● Sodium
● Potassium
● Cesium
● All of the Above
55. The electrons emitted from the metal surface are called _________
● Electron
● Photo Electron
● Diode
● None of the above
56. Photoelectrons is used in _________
● Television cameras
● Photo multiplier tubes
● Phototube
● All of the above
57. The conductivity of pure metals decreases with _________ in
temperature of metals.
● Decreases
● Increases
● Zero
● None of the above
58. The thermal conductivity of metals increase with _________ in
temperature of metals.
● Decreases
● Increases
● Zero
● None of the above
59. The electrical conductivity of pure metals decreases with _________
in temperature of metals.
● Decrease
● Increase
● Zero
● None of the above
Unit 2 - Dielectric Materials
(Total Marks 16)
60. The dielectric material are the _________
● Conducting material
● Semiconductor
● Insulating material
● None of the above
61. Very small amount of current flow through it is called as _________
● Current
● Leakage Current
● Knee Voltage
● Breakdown voltage
62. Which of the following fundamentals of Dielectric materials ?
● Polarization
● Electric dipole
● Capacitor
● All of the above
63. A capacitor is an electronic _________ component.
● Active
● Passive
● Active and passive
● None of the above
64. The ability of storing a charged in the form of electrostatic energy is
called a __________
● Resistance
● Inductance
● Capacitance
● Conductance
65. The dielectric constant 'k' is given by _________
● k = C . d / e
● k = C / d . e
● k = C . d . e
● k = d / e
66. The capacitive resistance is given by ?
● Xc = 2πfC
● Xc = 1/2πfC
● Xc = 1/2πC
● Xc = 1/2fC
67. Which of the following dielectric material used in capacitor ?
● Glass
● Mica
● Ceramic
● All of the above
68. Which of the following dielectric material used in capacitor ?
● Iron
● Mercury
● Fiber
● None of the above
69. How many types of Liquid dielectric material ?
● 1
● 3
● 2
● 5
70. Which of the following types of liquid dielectric materials ?
