This sets of mcq contains objectives on conducting materials, General Properties of Conductor, Electrical Conducting Materials - Copper, Aluminum and its applications, Materials of High & Low Resistivity-Constantan....
SET 1 of Conducting materials MCQ
1. Resistance of which material does not change with change in temperature?
A. Platinum
B. Constantan
C. Tungsten
D. Brass
Answer B
Marks 1
2. Constantan contains ----
A. copper & tin
B. tungsten & silver
C. copper and tungsten
D. copper and nickel
Answer D
Marks 1
3. Nichrome is an alloy of ----
A. Nickel, chromium and iron
B. Silver, copper & nickel
C. Aluminium, tin & copper
D. Chromium, manganese and copper
Answer A
Marks 1
4. Resistivity of a wire depends on ----
A. length
B. material
C. cross section area
D. none of the above
Answer B
Marks 1
5. Conductance is expressed in terms of -----
A. ohm / m
B. m / ohm
C. mho / m
D. mho
Answer D
Marks 1
6. Which of the following could be the value of resistivity of copper?
A. 1.7 x 108 ohm-cm
B. 1.7 x 10-6 ohm-cm
C. 1.6 x 105 ohm-cm
D. 1.7 x 102 ohm-cm
Answer B
Marks 1
7. Specific resistance of a substance is measured in ----
A. ohm
B. ohm/cm
C. ohm-cm
D. cm/ ohm
Answer C
Marks 1
8. The element of electric heater is made of ----
A. Copper
B. Steel
C. Carbon
D. Nichrome
Answer D
Marks 1
9. Bronze is an alloy of ---- .
A. copper - tin
B. copper- nickel
C. copper-cadmium
D. copper-chromium
Answer A
Marks 1
10. Which material is expected to have least resistivity?
A. Copper
B. Zinc
C. Lead
D. Aluminium
Answer A
Marks 1
SET 2 of Conducting materials MCQ
11. The values of temperature coefficient of resistance of a given conductor ----
A. Are the same at different temperatures
B. Are higher at higher temperatures
C. Are different at different temperatures
D. None of the above
Answer C
Marks 1
12. Poorest conductor of electricity is ----
A. Aluminum
B. Carbon
C. Steel
D. Silver
Answer B
Marks 1
13. Which of the following pairs is commonly used in thermocouples?
A. Iron-steel
B. Aluminium-tin
C. Silver-German silver
D. Copper- constantan
Answer D
Marks 1
14. Thermocouple work on which of the following effects?
A. Thomson effect
B. Seebeck effect
C. Peltier effect
D. Joule effect
Answer B
Marks 1
15. When a loop composed of two dissimilar metals could be made to carry a continuous current simply by maintaining the two junctions at different temperatures, the above effect is known as ----
A. Seebeck effect
B. Thomson effect
C. Peltier effect
D. Joule effect
Answer A
Marks 1
16. Which material has the highest electrical conductivity?
A. Silver
B. Aluminium
C. Copper
D. Iron
Answer A
Marks 1
17. Resistivity of copper is of the order of ----
A. 17.2 μ ohm-cm
B. 1.72 μ ohm-cm
C. 0.172 μ ohm-cm
D. 172 μ ohm-c
Answer B
Marks 1
18. Which of the following materials has negative resistance temperature coefficient?
A. Steel
B. Tungsten
C. Carbon
D. Tin
Answer C
Marks 1
19. Brass is an alloy of ---
A. copper-nickel
B. copper- tin
C. copper-zinc
D. copper-cadmium
Answer C
Marks 1
20. Which of the following has positive temperature coefficient?
A. Tungsten
B. Silicon
C. Dilute sulfuric acid
D. Germanium
Answer A
Marks 1
SET 3 of Conducting materials MCQ
21. All of the following have negative temperature coefficient except ----
A. Paper
B. Tungsten
C. Germanium
D. Rubber
Answer B
Marks 1
22. Which of the following has least resistivity?
A. Copper
B. Lead
C. Mercury
D. Aluminium
Answer A
Marks 1
23. Which of the following material is not used as fuse element?
A. Silver
B. Copper
C. Aluminium
D. Carbon
Answer D
Marks 1
24. The resistance temperature coefficient is defined as ----
A. increase in resistance per degree centigrade
B. decrease in resistance per degree centigrade
C. the ratio of increase in resistance per degree centigrade to the resistance at 0oC
D. the ratio of increases in resistance per degree centigrade to the rate of rise of resistance at 0 oC
Answer C
Marks 1
25. Filaments of electric bulbs are usually made of ----
A. Nichrome
B. Tungsten
C. Copper
D. Carbon
Answer B
Marks 1
26. Which of the following has negative coefficient of resistance?
A. Wire wound resistor
B. Metals
C. Non-metals
D. Thermister
Answer D
Marks 1
27. Materials having electrical conductivity much less than most of the metals but much greater than that of typical insulators, are known as ----
A. thermistors
B. varistors
C. semi-conductors
D. variable resistors
Answer C
Marks 1
28. Metals approach superconductivity conditions ----
A. near absolute zero temperature
B. near critical temperature
C. at critical point
D. under the conditions of high temperature and pressure
Answer A
Marks 1
29. Now a days, Copper is not used in ----
A. Brushes for electrical machines
B. Fuses
C. Transformer winding
D. Busbars
Answer A
Marks 1
30. Pure metal generally have ----
A. high conductivity and low temperature coefficient
B. high conductivity and large temperature coefficient
C. low conductivity and zero temperature coefficient
D. low conductivity and high temperature coefficient
Answer B
Marks 1
