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प्रश्न
Choose the correct alternative:
Alloys of metals usually have (greater/less) resistivity than that of their constituent metals.
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उत्तर
Alloys of metals usually have greater resistivity than that of their constituent metals.
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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 |
A heating element is marked 210 V, 630 W. Find the resistance of the element when connected to a 210 V dc source.
Plot a graph showing the variation of stopping potential with the frequency of incident radiation for two different photosensitive materials having work functions W1 and W2 (W1 > W2). On what factors does the (i) slope and (ii) intercept of the lines depend?
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:
The resistivity of a typical insulator (e.g., amber) is greater than that of a metal by a factor of the order of (1022/1023).
Fuse wire should have
What is the typical resistivity range for metals classified as conductors?
Which of the following describes the temperature dependence of semiconductors?
Which pair of materials best exemplifies semiconductors?
Which of the following materials would be classified as an insulator?
What is the primary reason copper is used in household wiring?
What is approximately how many times greater is the resistivity of insulators compared to metals?
