Advertisements
Advertisements
प्रश्न
What is Ohm's law? Explain how it is used to define the unit of resistance.
Advertisements
उत्तर
According to Ohm's law, the current (I) flowing through a wire is directly proportional to the potential difference (V) across it, provided its temperature remains the same.
Thus I α V.
V / I = Constant = R
V = IR
Here R is the resistance.
The unit of resistance is ohm (Ω).
One ohm (Ω) is the resistance of a conductor when a potential difference of one volt is applied to its ends and a current of one ampere flows through it.
संबंधित प्रश्न
By what other name is the unit joule/coulomb called?
How much work is done when one coulomb charge moves against a potential difference of 1 volt?
The unit for measuring potential difference is ______.
If the potential difference between the ends of a fixed resistor is halved, the electric power will become:
How is the electric potential difference between the two points defined? State its S.I. unit.
Electric cells having 2V potential difference each have been connected in the form of a battery. What will be the total potential difference of the battery in both cases?
A current of 0.2 A flows through a wire whose ends are at a potential difference of 15 V. Calculate:
(i) The resistance of the wire, and
(ii) The heat energy produced in 1 minute.
A cell of e.m.f 2.0 V and internal resistance 1Ω is connected to the resistors of 3Ω and 6Ω in series. Calculate:
(i) the current drawn from the cell,
(ii) the p.d. across each resistor,
(iii) the terminal voltage of the cell and
(iv) the voltage drop.
Electric potential is a ____________.
What does the positive and negative sign of potential convey?
