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प्रश्न
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).
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उत्तर
The resistivity of a typical insulator (e.g., amber) is greater than that of a metal by a factor of the order of 1022.
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.
Two wires of equal length, one of copper and the other of manganin have the same resistance. Which wire is thicker?
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?
A wire of length 1 m and radius 0.1 mm has a resistance of 100 Ω. Find the resistivity of the material.
How does the resistivity of a semiconductor change with rise of temperature ? Explain.
If R1 and R2 are filament resistances of a 200 W and a 100 W bulb respectively, designed to operate on the same voltage, then:
Choose the correct alternative:
Alloys usually have much (lower/higher) temperature coefficients of resistance than pure metals.
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 ______.
Fuse wire should have
If the last band on the carbon resistor is absent, then the tolerance is ______
