Q. Three resistances each of $1\ ohm,$ are joined in parallel. Three such combinations are put in series, then the resultant resistance will be
A) $9\ ohm$
B) $3\ ohm$
C) $1\ ohm$
D) $\frac{1}{3}ohm$
Explanation
(c) $\frac{1}{R} = \frac{1}{1} + \frac{1}{1} + \frac{1}{1} = \frac{3}{1} \Rightarrow R = \frac{1}{3}\ ohm$
Now such three resistance are joined in series, hence total
$R = \frac{1}{3} + \frac{1}{3} + \frac{1}{3} = 1ohm$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.