Question

Derivation of series combination.​

Answer 1

Answer:

In series combination, resister are connected end to end and current has a single path through the circuit but the potential difference varies across each resistor. Thus we can write as,

V = V1 + V2 + V3

according to Ohm's law V = IR So,  

V1 = I R1, V2 = I R2, V3 = I R3

V = I R1 + I R2 + I R3

V = I(R1+R2+R3)

V =IRe

All the individual resistances become equal to the equivalent resistance.

​or Re = R1 + R2 + R3......Rn

In parallel combination, each resistor'sone is connected to the positive terminal while the other end is connected to a negative terminal. The potential difference across each resistance is the same and the current passing through them is different.

V = V1 =V2=V3

I  = I1+ I2+I3

Current throught each resistor will be:

I1= V/R1 , I2 = V/R2 = I3 = V/R3

I = V (1/R1+ 1/R2+1/R3)  

In case of equivalent resistance I=V/Re

V/Re =  V (1/R1+ 1/R2+1/R3)

So the equivalnet resistance is the sum of all resistances

  1/Re = 1/R1+ 1/R2+1/R3.....

Answer 2

Explanation:

(i) When two or more resistors are connected in series, the total resistance of the combination is equal to the sum of all the individual resistances. (ii) When two or more resistors are connected in series, the same current flows through each resistor.