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प्रश्न
Is Ohm’s law universally applicable for all conducting elements? If not, give examples of elements which do not obey Ohm’s law.
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उत्तर
No, Ohm’s law is not universally applicable for all conducting elements. Vacuum diode semi-conductor is a non-ohmic conductor. Ohm’s law is not valid for it.
संबंधित प्रश्न
Graph showing the variation of current versus voltage for a material Ga As is shown in the figure. Identify the region of
(i) negative resistance
(ii) where Ohm's law is obeyed.
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.
What is Resistivity?
An electrical bulb is marked 200V, 100W. Calculate the electrical resistance of its filament. If five such
bulbs are connected in series to a 200V supply, how much current will flow through them?
Keeping the p.d. constant, the resistance of a circuit is halved. The current will become:
(a) one-fourth
(b) four time
(c) half
(d) double
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?
- Draw a V-I graph for a conductor obeying Ohm’s law.
- What does the slope of V–I graph for a conductor represent?
Show by a diagram how two resistors R1 and R2 are joined in parallel. Obtain an expression for the total resistance of the combination.
Calculate the effective resistance across AB?
Define ampere and volt with respect to Ohm’s law.
State the limitations of Ohm’s law.
What are non-ohmic conductors? Give one exmaple. Draw a current-voltage graph for a non-ohmic conductor.
Choose the correct alternative.
Which of the following is an ohmic conductor?
Obtain the macroscopic form of Ohm’s law from its microscopic form and discuss its limitation.
A student carries out an experiment and plots the V-I graph of three samples of nichrome wire with resistances R1, R2 and R3 respectively. Which of the following is hue?
State Ohm’s law? How can it be verified experimentally? Does it hold good under all conditions? Comment.
Two cells of same emf E but internal resistance r1 and r2 are connected in series to an external resistor R (Figure). What should be the value of R so that the potential difference across the terminals of the first cell becomes zero.
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.
