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प्रश्न
What is Ohm's law? Explain how it is used to define the unit of resistance.
उत्तर
According to Ohm's law, the current (I) flowing through a wire is directly proportional to the potential difference (V) across it, provided its temperature remains the same.
Thus I α V.
V / I = Constant = R
V = IR
Here R is the resistance.
The unit of resistance is ohm (Ω).
One ohm (Ω) is the resistance of a conductor when a potential difference of one volt is applied to its ends and a current of one ampere flows through it.
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संबंधित प्रश्न
Name a device that helps to maintain a potential difference across a conductor.
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Keeping the potential difference constant, the resistance of a circuit is doubled. By how much does the current change?
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| Potential differences, V (in volts) | : | 2.5 | 5.0 | 10.0 | 15.0 | 20.0 | 25.0 |
| Current, I (in amperes) | : | 0.1 | 0.2 | 0.4 | 0.6 | 0.8 | 1.0 |
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