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प्रश्न
The circuit depicted in the figure is employed for studying Ohm’s Law. Instead of using a standard resistor, a student opts for a glass tube filled with mercury (tube 1), connected to the circuit through two electrodes, E1 and E2. He records the readings of the ammeter and voltmeter, thereby calculating the resistance. The student repeats the experiment by substituting tube 1 with tube 2, where the same amount of mercury fills tube 2.
Neglecting internal resistance of the cell use (> or < or =) to compare:
- the resistance in both the cases.
- the voltmeter readings in both the cases.
- the specific resistance in both the cases.
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उत्तर
- The resistance of tube 2 is less than the resistance of tube 1 because resistance depends directly on the length and inversely on the area of the resistor, and tube 2 is thicker and shorter than tube 1.
- The voltmeter reading for tube 1 is the same as the voltmeter reading for tube 2 because, according to Ohm’s law, the potential difference across a resistor depends only on the current applied, not on the resistance of the resistor.
- As the specific resistance of a resistor is independent of its dimensions but depends only on the contained material, and since here both tubes contain only mercury, the specific resistance in both cases is the same.
संबंधित प्रश्न
Find the resistance of a conductor if 0.24 A current is passing through it and a potential difference of 24 V is applied across it.
When a 12 V battery is connected across an unknown resistor, there is a current of 2.5 mA in the circuit. Find the value of the resistance of the resistor.
The relationship between the potential difference and the current in a conductor is stated in the form of a law.
1) Name the law.
2) What does the slope of V-I graph for a conductor represent?
3) Name the material used for making the connecting wire.
The resistors R1, R2, R3 and R4 in the figure given below are all equal in value.
What would you expect the voltmeter A, B and C to read assuming that the connecting wires in the circuit have negligible resistance?
A car bulb connected to a 12 volt battery draws 2 A current when glowing. What is the resistance of the filament of the bulb? Will the resistance be more same or less when the bulb is not glowing?
In an experiment of verification of Ohm’s law following observations are obtained.
|
Potential difference V (in volt) |
0.5 | 1.0 | 1.5 | 2.0 | 2.5 |
| current I (in ampere) | 0.2 | 0.4 | 0.6 | 0.8 | 1.0 |
Draw a V-I graph and use this graph to find:
- the potential difference V when the current I is 0.5 A,
- the current I when the potential difference V is 0.75 V,
- the resistance in a circuit.
In the circuit shown below in Fig, calculate the value of x if the equivalent resistance between A and B is 4 Ω.
What is non-ohmic resistor?
State microscopic form of Ohm’s law.
State Ohm's Law. Represent it mathematically.
