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प्रश्न
Plastic insulation surrounds a wire having diameter d and length l as shown above. A decrease in the resistance of the wire would be produced by an increase in the ______.
विकल्प
length l of the wire
diameter d of the wire
temperature of the wire
thickness of the plastic insulation
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उत्तर
Plastic insulation surrounds a wire having diameter d and length l as shown above. A decrease in the resistance of the wire would be produced by an increase in the diameter d of the wire.
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संबंधित प्रश्न
List the factors on which the resistance of a conductor in the shape of a wire depends.
Fill in the following blanks with suitable words:
Copper is a good .......... Plastic is an ..........
What is the general name of the substances having infinitely high electrical resistance?
Name the electrical property of a material whose symbol is "omega".
What happens to the resistance as the conductor is made thicker?
Give two examples of substances which are good conductors of electricity. Why do you think they are good conductors of electricity?
How does the resistance of a conductor depend on:
area of cross-section of the conductor?
Resistance of a metal wire of length 5 m is 100 Ω . If the area of cross - section of the wire is `3 × 10^-7 "m"^2` , Calculate the resistivity of the metal .
The element used almost exclusively for filaments of incandescent lamps:
Use the data in the Table given below to answer the following –
Which material is the best conductor?
Table give below Electrical resistivity of some substances at 20°C
| Electrical resistivity of some substances at 20°C | ||
| − | Material | Resistivity (Ω m) |
| Conductors |
Silver | 1.60 × 10−8 |
| Copper | 1.62 × 10−8 | |
| Aluminium | 2.63 × 10−8 | |
| Tungsten | 5.20 × 10−8 | |
| Nickel | 6.84 × 10−8 | |
| Iron | 10.0 × 10−8 | |
| Chromium | 12.9 × 10−8 | |
| Mercury | 94.0 × 10−8 | |
| Manganese | 1.84 × 10−6 | |
| Alloys |
Constantan (alloy of Cu and Ni) |
49 × 10−6 |
| Manganin (alloy of Cu, Mn and Ni) |
44 × 10−6 | |
| Nichrome (alloy of Ni, Cr, Mn and Fe) |
100 × 10−6 | |
| Insulators | Glass | 1010 − 1014 |
| Hard rubber | 1013 − 1016 | |
| Ebonite | 1015 − 1017 | |
| Diamond | 1012 − 1013 | |
| Paper (dry) | 1012 | |
