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प्रश्न
How does the resistance of a wire change when:
its material is changed to one whose resistivity is three times?
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उत्तर
Resistance,
`R=l/A`
where l = length of wire
A= area of cross-section of the wire
When the material is changed to one whose resistivity is three times:
`R=(3rho)/A=3R`
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| Electrical resistivity of some substances at 20°C | ||
| − | Material | Resistivity (Ω m) |
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