Question

If three wires of equal resistance are given then number of combinations they can be made to give difference resistance is

• A. $4$
• B. $3$
• C. $5$
• D. $2$

Answer 1

Answer: (A)

$4$

From 3 equal resistance (each being equal to R), we can have the following combinations:-

All three resistance in series, net resistance being equal to $3R$

All three resistance in parallel, net resistance being equal to $\frac{R}{3}$

Two resistance in parallel and the third being in series with them, net resistance being equal to $\frac{R}{3}$

Two resistance in series and the third being in parallel with all of them, net resistance being equal to $\frac{2R}{3}$