This sets of mcq contains conducting materials, General Properties of Conductor, Introduction to Superconductivity and Super Conductors in part 2...
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SET 1 of general properties of conducting materials MCQ
1. ------- is used for making rheostat.
A. constantan
B. nichrome
C. tungsten
D. copper
Answer A
Marks 1
2. Overhead transmission lines are made up of ----
A. Aluminium
B. ACSR
C. Steel
D. Copper
Answer B
Marks 1
3. Thermal Bi-metals are used in ------ .
A. overload relay
B. generators
C. motors
D. transformers
Answer A
Marks 1
4. Mercury ------- linearly with temperature change.
A. Expands
B. Contracts
C. Both A & B
D. changes
Answer C
Marks 1
5. A good electric contact material should have all of the following properties except ---- .
A. high resistivity
B. high resistance to corrosion
C. good thermal conductivity
D. high melting point
Answer A
Marks 1
6. Most of the common metals have _____ structure.
A. linear
B. hexagonal
C. orthorhombic
D. cubic
Answer D
Marks 1
7. Which of the following affect greatly the resistivity of conductors?
A. Composition
B. Pressure
C. Size
D. Temperature
Answer A
Marks 1
8. _____ is a hard solder.
A. Tin-lead
B. Tin-silver-lead
C. Copper-zinc
D. None of the above
Answer C
Marks 1
9. Addition of 0.3 to 4.5% silicon to iron _____ the electrical resistivity of iron.
A. increases
B. decreases
C. does not change
D. largely decreases
Answer A
Marks 1
10. Super conductivity can be destroyed by ---- .
A. adding impurities
B. reducing temperatures
C. application of magnetic field
D. any of the above
Answer C
Marks 1
SET 2 of general properties of conducting materials MCQ
11. One of the materials used in thermocouple for measurement of temperature is/are ---- .
A. Platinum
B. Copper
C. Nickel
D. All of above
Answer D
Marks 1
12. The resistivity of a metal is a function of temperature because ----
A. the amplitude of vibration of the atoms varies with temperature
B. the electron density varies with temperature
C. the electron gas density varies with temperature
D. All of above
Answer A
Marks 1
13. Carbon resistors are used extensively because they are ----
A. easy to make
B. compact
C. inexpensive
D. all of the above reasons
Answer D
Marks 1
14. Carbon rods are used in wet and dry cells because ----
A. carbon rod serves as conductor
B. carbon can resist the attack of battery acid
C. both (A) and (B)
D. either (A) or (B)
Answer C
Marks 1
15. Which of the following are non-conductors of electricity?
A. Non-metal solids except carbon
B. Air and most other gases
C. Pure water and liquids in general except mercury
D. All of the above
Answer D
Marks 1
16. Carbon bearings are used under which of the following conditions?
A. Where lubrication is difficult or impossible
B. Where corrosive chemical action exists
C. Where high temperature exists
D. All of the above
Answer D
Marks 1
17. Which of the following high resistance materials has the highest operating temperature?
A. Canthal
B. Manganin
C. Nichrome
D. Eureka
Answer A
Marks 1
18. Steel wire is used as ----
A. overhead telephone wire
B. earth wire
C. core wire of ACSR
D. all of the above
Answer D
Marks 1
19. Low resistivity materials are used in ----
A. transformer, motor and generator windings
B. transmission and distribution lines
C. house wiring
D. all above applications
Answer D
Marks 1
20. Platinum is used in ----
A. electrical contacts & thermocouple
B. heating element in high temperature furnace
C. grids of special purpose vacuum tubes
D. all of the above
Answer D
Marks 1
SET 3 of general properties of conducting materials MCQ
21. Which of the following is an advantage of stranded conductor over equivalent single conductor?
A. Less liability to link
B. Greater flexibility
C. Less liability to break
D. All of the above
Answer D
Marks 1
22. Due to which of the following reasons, copper and aluminium are not used for heating elements?
A. Both have great tendency for oxidation
B. Both have low melting point
C. Very large length of wires will be required
D. All of the above
Answer C
Marks 1
23. Copper, even though costly, finds use in the windings of electrical machines because ----
A. copper points offer low contact resistance
B. copper can be easily soldered and welded
C. copper windings are less bulky and the machines become compact
D. all of the above
Answer D
Marks 1
24. Which of the following materials is used for making coils of standard resistances?
A. Copper
B. Nichrome
C. Manganin
D. Platinum
Answer C
Marks 1
25. Substances whose specific resistance abruptly decreases at very low temperature are called as ---- .
A. insulators
B. conductors
C. semiconductors
D. superconductors
Answer D
Marks 1
26. Which of the following materials is the best conductor of electricity?
A. Silver
B. Aluminium
C. Copper
D. Carbon
Answer A
Marks 1
27. Thermocouples are mainly used for the measurement of ----
A. temperature
B. resistance
C. eddy currents
D. coupling co-efficient
Answer A
Marks 1
28. Due to which of the following fact, in India, aluminium is replacing copper?
A. Aluminium is more ductile and malleable than copper
B. Aluminium is available in plenty, cheaper and lighter than copper
C. Aluminium has lower resistivity than that of copper
D. Aluminium has less temperature co-efficient than copper
Answer B
Marks 1
29. If the resistance of a conductor does not vary in accordance with Ohm's law, it is known as ----
A. non-linear conductor
B. reverse conductor
C. bad-conductor
D. non-conductor
Answer A
Marks 1
30. Spark plug makes use of which of the following materials for insulation?
A. Porcelain
B. Slate
C. Asbestos
D. Glass
Answer A
Marks 1
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