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प्रश्न
The graph between V and I for a conductor is a straight line passing through the origin.
What should remain constant in a statement of this law?
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उत्तर
Ohm's law is true only if the temperature of the conductor is constant.
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संबंधित प्रश्न
A low voltage supply from which one needs high currents must have very low internal resistance. Why?
What is Resistivity?
The graph between V and I for a conductor is a straight line passing through the origin.
Which law is illustrated by such a graph?
What is the necessary condition for a conductor to obey Ohm’s law?
What length of copper wire of resistivity 1.7 × 10-8 Ω m and radius 1 mm is required so that its resistance is 2Ω?
Two metallic spheres A and B kept on insulating stands are in contact with each other. A positively charged rod P is brought near the sphere A as shown in the figure. The two spheres are separated from each other, and the rod P is removed. What will be the nature of charges on spheres A and B?
Consider the sacle of voltmeter shown in the diagram and answer the following questions :
(a) What is the least count of the voltmeter?
(b) What is the reading shown by the voltmeter ?
(c) If the voltmeter is connected across a resistor of 20 `Omega` how much current is flowing through the resistor?
- Name and state the law which relates the potential difference and current in a conductor.
- What is the necessary condition for a conductor to obey the law named above in part (a) ?
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State Ohm’s law.
Define Current density.
State microscopic form of Ohm’s law.
The resistance of a nichrome wire at 0°C is 10Ω. If its temperature coefficient of resistivity of nichrome is 0.004/ °C, find its resistance of the wire at boiling point of water. Comment on the result.
The unit of specific resistance is ____________.
A current of 2amp flowing through a conductor produced 80 joule of heat in 10 sec. The resistance of the conductor is:-
The heat produced by a 100 w heater in 2 minute is equal to
Let the resistance of an electrical device remain constant, while the potential difference across its two ends decreases to one fourth of its initial value. What change will occur in the current through it? State the law which helps us in solving the above stated question.
The resistance of a resistor is reduced to half of its initial value. If other parameters of the electrical circuit remain unaltered, the amount of heat produced in the resistor will become ______.
The voltage - current readings of a certain material are shown in the table given below:
| Voltage (V) | 10 V | 20 V | 30 V |
| Current (I) | 2 A | 3 A | 4 A |
Study the table.
- State whether the conductor used is ohmic or non-ohmic.
- Justify your answer.
- State Ohm's law.
