Resistance and ohm's law
  Resistance:-   -           Property of substance which opposes the flow of electrons through it.   -           Unit : ohm (Ω)    -           Being applied voltage remaining constant, if the resistance is high then the current flow will be less.       Ohm’s Law:-   -           Remaining physical conditions such as temperature, strain etc., of the conductor as constant, the current flowing through a conductor is directly proportional to the potential difference across the conductor.   -           IαV, Temparature constant.   -           1/R is the proportionality constant.   -           By removing the proportionality constant by putting equality constant.   I=V/R;   ...