EX
13. Define Ohm's law and also explain ohmic and non ohmic materials?
Answers
law stating that electric current is proportional to voltage and inversely proportional to resistance.
That substance which obeys ohm's law. The resistance of substance does not depends upon current and voltage. For example:wire , resistor. Wire is ohmic substance because it obeys ohm;s law. Non- ohmic subtance: That substance which does not obeys ohm's law.
Answer:
Ohms law { V = IR } :
According to ohms law, the current flowing in a conductor is directly proportional to the potential difference applied across its ends provided that the physical conditions and the temperature of the conductor remain constant.
Ohmic resistors ( materials ) :
The conductors which obey the Ohms law are called the ohmic resistors ( or linear resistances ).
Examples :
- All metallic conductors ( silver, aluminium, copper etc.. )
- Copper sulphate solution with copper electrodes
- Dilute sulphuric acid
- Nichrome
Non-ohmic resistors ( materials ) :
The conductors which do not obey the ohms law are called the non-ohmic resistors ( or non-linear resistances ).
Examples :
- Filament of a bulb
- Junction diode
- Solar cell
- LED