Question

Three resistor of resistance r1 r2 r3 are connected in series and parallel write expression for the eauivalent resistance of the combination in each case

Answer 1

When resistors are connscted in series, their potential differences varies

Therefore,

V=v1+v2+v3

IR=IR1+IR2+IR3

since current is same in series

IR=I(R1+R2+R3)

CANCELLING I(CURRENT)

R=R1+R2+R3

when connected in parellel

Their current tends to divide

Therefore

I=I1+I2+I3

V/R=V/R1+V/R2+V/R3

Since potential difference is same

Cancel V (potential difference)

1/R=1/R1+1/R2+1/R3