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प्रश्न
Define the unit of resistance (or Define the unit "ohm").
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उत्तर
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
What do the letters p.d. stand for?
What is meant by saying that the electric potential at a point is 1 volt?
What is the SI unit of potential difference?
State whether a voltmeter has a high resistance of a low resistance. Give reason for your answer.
b. The values of potential difference V applied across a resistor and the correponding values of current I flowing in the resistor are given below:
| Potential difference, 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 |
Plot a graph between V and I, and calculate the resistance of the resistor.
c. Name the law which is illustrated by the above V-I graph.
Calculate the power used in the 2 Ω resistor in each of the following circuits: a 4 V battery in parallel with 12 Ω and 2 Ω resistors.
Explain why potential difference is always less than the e.m.f. of a cell?
A 10 m long wire of a particular material is of resistance 5Ω What will be the resistance of 10m long wire of the same material but the double radius.
A cylindrical conductor of length l and uniform area of cross section A has resistance R. Another conductor of length 2l and resistance R of the same material has area of cross section.
Twenty-seven drops of same size are charged at 220 V each. They combine to form a bigger drop. Calculate the potential of the bigger drop.
