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प्रश्न
Choose the correct alternative:
The resistivity of the alloy manganin is nearly independent of/increases rapidly with increase of temperature.
उत्तर
The resistivity of the alloy, manganin, is nearly independent of increase of temperature.
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संबंधित प्रश्न
Two wires of equal length, one of aluminium and the other of copper have the same resistance. Which of the two wires is lighter? Hence explain why aluminium wires are preferred for overhead power cables.
(ρAl = 2.63 × 10−8 Ω m, ρCu = 1.72 × 10−8 Ω m, Relative density of Al = 2.7, of Cu = 8.9.)
What conclusion can you draw from the following observations on a resistor made of alloy manganin?
| Current A |
Voltage V |
Current A |
Voltage V |
| 0.2 | 3.94 | 3.0 | 59.2 |
| 0.4 | 7.87 | 4.0 | 78.8 |
| 0.6 | 11.8 | 5.0 | 98.6 |
| 0.8 | 15.7 | 6.0 | 118.5 |
| 1.0 | 19.7 | 7.0 | 138.2 |
| 2.0 | 39.4 | 8.0 | 158.0 |
Choose the correct alternative:
Alloys of metals usually have (greater/less) resistivity than that of their constituent metals.
A heating element is marked 210 V, 630 W. What is the value of the current drawn by the element when connected to a 210 V dc source?
A heating element is marked 210 V, 630 W. Find the resistance of the element when connected to a 210 V dc source.
Two wires of equal length, one of copper and the other of manganin have the same resistance. Which wire is thicker?
A wire of length 1 m and radius 0.1 mm has a resistance of 100 Ω. Find the resistivity of the material.
A uniform wire of resistance 100 Ω is melted and recast as a wire whose length is double that of the original. What would be the resistance of the wire?
What length of a copper wire of cross-sectional area 0.01 mm2 will be needed to prepare a resistance of 1 kΩ? Resistivity of copper = 1.7 × 10–8 Ωm
How does the resistivity of a semiconductor change with rise of temperature ? Explain.
Choose the correct alternative:
Alloys usually have much (lower/higher) temperature coefficients of resistance than pure metals.
Fuse wire should have
If the last band on the carbon resistor is absent, then the tolerance is ______
