three resistors of 6 ohm,2 ohm and x are connected in series to a cell of emf 1.5 V.the current registered is (1/6) A.calculate the value of x

For the series combination,the equivalent resistance is given by

R=R1+R2+R3

So

R=6+2+x=(8+x) ohm

Given that,V=1.5 V and I=(1/6) A

Using Ohm's law

V=IR

1.5=(1/6) X (8+x)

8+x=9

or x=9-8=1 ohm