Power is directly proportional as well as inversely proportional by two formulae.How does one justify?
P=V2/R as well as p=I2 R.
This means that for a given current, (i.e, when current is kept constant) Power is directly proportional to resistance.
eg, when a number of appliances are connected in series, the same current passes though all and the power dissipated in each will be directly proportional to their resistances.
For a given constant voltage, the power is inversely proportional to resistance.
For eg; when a number of appliances are connected in parallel across the same voltage, then the power dissipated in each is inversely proportional to their resistances.