Question

derive laws of reristance in series so as to explain equivalent resistance of circuit ​

Answer 1

The equivalent resistance is the algebraic sum of the resistances (Equation 10.3. 2): RS=R1+R2+R3+R4+R5=20Ω+20Ω+20Ω+20Ω+10Ω=90Ω. The current through the circuit is the same for each resistor in a series circuit and is equal to the applied voltage divided by the equivalent resistance: I=VRS=9V90Ω=0.1A.