Question

The effective resistance in between the points $A$ and $B$ in the circuit given below is

• A. $23\Omega$
• B. $32\Omega$
• C. $12\Omega$
• D. $45\Omega$

Answer 1

The correct option is B $32\Omega$

5 ohm and 15 ohms are in series & in Parallel with 20 ohm.

Hence 20 ohm is in parallel with 20 ohm.(attachment 1)

Hence $\frac{1}{R}=\frac{1}{20}+\frac{1}{20}$

$R=10ohm$

Now 10 & 6 are in series and in parallel with 48 ohm resistor.

Hence 16 ohm nd 48 ohm r in parallel. (attachment 3).

Hence $\frac{1}{R}=\frac{1}{16}+\frac{1}{48}$

$R=12ohm.$

LHS

10 & 8 ohms are in series & in Parallel with 9 ohm.

Hence 18 & 9 are in parallel.

$\frac{1}{R}=\frac{1}{9}+\frac{1}{18}$

$R=6ohm..$

will get one triangle in which resistance are in series : $14+12+6$

$=32ohm.$