Electrical Engineering - Series Circuits - Discussion

For an Electrical circuit.

P=I*I*Req,
Req= equivalent resistance of the circuit.
We can also write it as P=V*V/Req.

Now
case1- one 220ohm resistance Req=220ohm,
case2-Two 220ohm resistance.
Req=2*220ohm ,P2=P1/2,
Similarly P3=P1/3.
P4=P1/4.
Hence max power is dissipated in the case 1.

Keeping voltage constant power is inversely proportional to resistance, so resistance increases power decrease.

See.

When any resistor connected in series combination, then. Power is directly proportional to Current (I). So, A/q to find current _we have voltage and resistance.

Therefore, P=[I]2 (square)R. So, when we find the value of current, we will see that (a) option have a maximum value.

1. Since voltage is constant (120 v) and P = V^2/R which implies that power is inversely proportional to resistance. henceforth power will dissipate more when resistance is least i.e option A.

OR
2. P = I^2R. here power depends on the square of the current and current is inversely proportional to the current(ohm's law). I = more when resistance is less hence more current = more power PERIOD.