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(a) What is meant by saying that the potential difference between two points is 1 volt? Name a device that helps to measure the potential difference across a conductor.(b)Why does the connecting cord of an electric heater not glow hot while the heating element does?(c) Electrical resistivities of some substances at 20°C are given below: Silver 1.60 × 10−8 Ωm Copper 1.62 × 10−8 Ωm Tungsten 5.20 × 10−8 Ωm Iron 10.0 × 10−8 Ωm Mercury 94.0 × 10−8 Ωm Nichrome 100 × 10−6 Ωm Answer the following questions in relation to them:(i) Among silver and copper, which one is a better conductor? Why?(ii) Which material would you advise to be used in electrical heating devices? Why? |
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Answer» (a) What is meant by saying that the potential difference between two points is 1 volt? Name a device that helps to measure the potential difference across a conductor. (b)Why does the connecting cord of an electric heater not glow hot while the heating element does? (c) Electrical resistivities of some substances at 20°C are given below:
Answer the following questions in relation to them: (i) Among silver and copper, which one is a better conductor? Why? (ii) Which material would you advise to be used in electrical heating devices? Why? |
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