Question

write the write answer ​

Answer 1

$\boxed{\boxed{Answer:-}}$

$\huge\purple{Data :-}$

R1 = R2 = R3 = 20 ohm

the equivalent resistance Rp of R1 and R2 is given by

$\frac{1}{rp} = \frac{1}{r1} + \frac{1}{r2} = \frac{1}{20 \: ohm} + \frac{1}{20 \: ohm} \\ = \frac{2}{20 } = \frac{1}{10 } \\ = rp = 10 \: ohm$

The equivalent resistance of Rp and R3 in series is

Rs = Rp + R3 = ( 10 + 20 ) ohm = 30 ohm

...•... The equivalent resistance of the combination is 30 ohm

Answer 2

As given the firs two resistances are in parallel

• Let  us write R1=20, R2=20
• Now add in parallel that is written as 1/rp=(1/R1)+(1/R2)=(1/20)+(1/20)
• 0.05+0.05=1/rp
• rp=10 ohm
• Now it is connected with series resistance r=20
• Therefore the equivalent resistance is 10+20=30
• That is 30 ohm.