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प्रश्न
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.
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उत्तर
a. Here, the ratio of `V/1` for different readings is:
(i) `(10 V)/(2 A) = 5 Ω`
(ii) `(20 V)/(3 A) = 6.66 Ω`
(iii) `(30 V)/(4 A) = 7.5 Ω`
Here, the ratio is not constant, so the conductor is non-ohmic.
b. The ratio of `V/I` remains constant for all values of V and I in an ohmic conductor. Plotting current I against potential difference V results in a straight line that passes through the origin on a graph. Thus, the conductor in question is not ohmic.
c. Ohm's law states that, under constant physical conditions and conductor temperature, the current flowing in a conductor is directly proportional to the potential difference applied across its ends.
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संबंधित प्रश्न
Let the resistance of an electrical component remains constant while the potential difference across the two ends of the component decreases to half of its former value. What change will occur in the current through it?
Name the law which is illustrated by the above V−I graph.
Four resistances of 16 ohms each are connected in parallel. Four such combinations are connected in series. What is the total resistance?
- Draw a V-I graph for a conductor obeying Ohm’s law.
- What does the slope of V–I graph for a conductor represent?
In a conductor 6.25 × `10^16` electrons flow from its end A to B in 2 s. Find the current flowing through the conductor (e = 1.6 × `10^-19` C)
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.
Fig. represents the circuit used for the verification of ohm's law. Label the different parts from A and F. State the function of each.
Tick(✓) the correct choice in the following:
Ohm's law is applicable to
State microscopic form of Ohm’s law.
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 ______.
