Question

plz solve question no. 4 and 5​

Answer 1

pls refer the attachment first for better understanding

(Q 4)

First we need to find the potential across each resistor

Then consider the center point at ' x '

Now rearrange the resistors ( like I have done in the attachment )

Between V and x

Two resistors both of resistance 8 ohm are connected in parallel with each other

$\implies{ Rp = \frac{R1 \times R2}{R1 + R2} }$

$\implies{ Rp = \frac{64}{16}}$

$\implies{ Rp = 4 ohm}$

Between V and 0

4 ohm and 4 ohm are connected in Series with each other

$\implies{ Rs = R1 + R2}$

$\implies{ Rs = 8 \: ohm}$

8 ohm and 12 ohm are connected in parallel with each other

$\implies{ Rp = \frac{8 \times 12}{20} }$

$\boxed{ Rp = 4 .8 ohm}$

(Q5)

Between V and 0

All the four resistors are connected in parallel to each other

$\implies{\frac{1}{Rp} = \frac{1}{R1} + \frac{1}{R2} + \frac{1}{R3} + \frac{1}{R4}}$

$\implies{\frac{1}{Rp} = \frac{1}{10} + \frac{1}{10} + \frac{1}{10} + \frac{1}{10}}$

$\implies{Rp = \frac{10}{4} }$

$\boxed{ Rp = 2.5 ohm}$