Question

By using six resistors of resistances 1 $\Omega$ and four resistors of resistance 2$\Omega$, Rakesh constructed two identical letters A and connected them as shown in the circuit. Rakesh needs to determine the current flowing through the circuit when this is connected in a circuit. For that, he first determined the effective resistance between A and B. Can you help Rakesh determine the value of the effective resistance?

• A. 3.2 $\Omega$
• B. 1.6 $\Omega$
• C. 2.8 $\Omega$
• D. 5.6 $\Omega$

Answer 1

The correct option is D 5.6 $\Omega$

We have to calculate equivalent resistance across AB, connect A and B.

Now we see that two$\left(2\Omega \right)$ resistors are in series.

So equivalent circuit becomes: FIg(II)

Now $(4\Omega ,1\Omega )$ are in parallel, so equivalent circuit becomes:Fig(ii)

Now we see that all resistance are in series:

So Req$=1\Omega +\frac{4}{5}\Omega +1\Omega +1\Omega +\frac{4}{5}\Omega +1$

$=4\Omega +\frac{8}{5}$

$=\frac{28}{5}=5.6\Omega$