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प्रश्न
How does the resistivity of a semiconductor change with rise of temperature ? Explain.
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उत्तर
As the temperature increase number of charge particle (holes and electrons) also increases. So, current increase and resistance decreases.
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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 |
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A heating element is marked 210 V, 630 W. Find the resistance of the element when connected to a 210 V dc source.
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?
Choose the correct alternative:
The resistivity of the alloy manganin is nearly independent of/increases rapidly with increase of temperature.
The resistivity of alloy manganin is ______.
