Question

calculate resistance​

Answer 1

IF YOU LOOK AT IT CAREFULLY IT IS A EXTENDED WHEATSTONE BRIDGE HENCE THE 3 OHM RESISTORS IN THE MIDDLE ARE NOT COUNTED

9 ohm and 9 ohm are in parallel

$rp = \frac{9 \times 9}{9 + 9} \\ rp = \frac{9}{2} \\ rp = 4.5ohm$

I HOPE THIS HELPS ( ╹▽╹ )

Answer 2

ans..

by simplifying,

1/r'= 1/21+1/3

=1+7/21 by lcm

=8/21

so,

r'=21/8