Advertisements
Advertisements
प्रश्न
What is a resistance? Define it with respect to Ohm’s law,
Advertisements
उत्तर
In the flow of current in a conductor, electrons are drifted. During this drift or flow, electrons mutually collide against each other and the atoms of the conductor. These collisions give rise to some obstruction to the flow of electrons. This opposition or obstruction offered by a conductor to the flow of electrons is called ‘Resistance’. According to Ohm’s law, the ratio between potential difference V and the current i, is a constant provided the temperature and physical conditions of the conductor remain unaltered. As such the ratio V/I is called the resistance, i.e., ‘Ohmic resistance’ of the conductor.
संबंधित प्रश्न
Draw a V-I graph for a conductor at two different temperatures. What conclusion do you draw from your graph for the variation of resistance of conductor with temperature?
In series combination of resistances ______.
To increase the effective resistance in a circuit, the resistors are connected in _______________ .
What material is used for making wire to prepare heating coils? Give a reason.
State the effect of rise in temperature on the resistance of semi-conductors.
Write an expression for calculating electrical power in terms of current and resistance.
You are provided with three resistors of resistance 1.0 Ω, 2.0 Ω and 3.0 Ω How would you connect them to obtain the total effective resistance 1.5 Ω? Draw diagram of the arrangement and check it by calculations.
Calculate the quantity of heat that will be produced in a coil of resistance 75 Ω if a current of 2A is passed through it for 2 minutes.
Show how you would connect three resistors, each of resistance 6 Ω, so that the combination has a resistance of 4 Ω.
