Advertisements
Advertisements
प्रश्न
State the limitations of Ohm’s law.
Advertisements
उत्तर
There are two main limitations:
(i) Temperature,
(ii) Physical condition of the conductor.
It is found that the ratio V/I is mo longer constant when the temperature is not kept constant. Generally, resistance increases with the rise in the temperature of the conductor.
Physical conditions of any conductor mainly include:
(i) Its length,
(ii) Its cross-sectional area,
(iii) The kind of material.
If there is no change in any of the above three conditions and also other condition like temperature remains constant, then Ohm’s law holds good, i.e., the ratio V/I remains constant.
संबंधित प्रश्न
Write the SI unit of resistivity
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
Which of the following is an ohmic resistance?
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)
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?
Calculate the current flowing through a wire of resistance 5 Ω connected to a battery of potential difference 3 V.
State Ohm’s law.
Define temperature coefficient of resistance.
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 ______.
