Resistance is a measure of the opposition to current flow in an electrical circuit. Resistance is measured in ohms, symbolized by the Greek letter omega (Ω). … Insulators: Materials that present high resistance and restrict the flow of electrons.
What is electrical resistance and its unit?
The SI unit of electrical resistance is the ohm (Ω), while electrical conductance is measured in siemens (S) (formerly called “mho”s and then represented by ℧). … All objects resist electrical current, except for superconductors, which have a resistance of zero.
What is meant by electrical resistance of a conductor Class 10?
Resistance is defined as the property of a conductor to resist the flow of charges through it. The resistance of conductor is numerically given as the ratio of potential difference across its length to the current flowing through it.
What is electrical resistance formula?
Resistance has units of ohms (Ω), related to volts and amperes by 1 Ω = 1 V/A. There is a voltage or IR drop across a resistor, caused by the current flowing through it, given by V = IR.
What causes electrical resistance?
An electric current flows when electrons move through a conductor, such as a metal wire. The moving electrons can collide with the ions in the metal. This makes it more difficult for the current to flow, and causes resistance.
What do you mean by 1 ohm?
One ohm is equal to the resistance of a conductor through which a current of one ampere flows when a potential difference of one volt is applied to it.
What is called specific resistance?
Specific resistance is defined as the resistance offered per unit length and unit cross-sectional area when a known amount of voltage is applied. The mathematical representation is as follows: ρ=RAL.
What is current formula?
The current is the ratio of the potential difference and the resistance. It is represented as (I). The current formula is given as I = V/R. The SI unit of current is Ampere (Amp).