Question

Drive an expression for the equivalent resistance of three resistance connected in series and parallels.

Answer 1

Series- V=V1+V2+V3 (By properties)
            therefore, IR=IR1+IR2+IR3 (V=IR)
                             IR=I(R1+R2+R3)
                             R=R1+R2+R3
Parallel- I=I1+I2+I3 (By properties)
              therefore, V/R=V/R1+V/R2+V/R3 (I=V/R)
                               V/R=V(1/R1+1/R2+1/R3)
                               1/R=1/R1+1/R2+1/R3