Question

if reading voltmeter of v is zero find eqivalent resistance between A and B ?
please ans this question it's urgent step by step ​

Answer 1

Explanation:

if voltmeter showing null deflection , the pd across the voltmeter is zero

therefore under balanced condition

1. 22 x22 /44 = 11ohm

2. 20 x20 /40 = 10ohm

3. 11 + 10 =21 ohm

4.3 + 4 = 7ohm

5. 3 +2 = 5ohm

6.[ (10 x X )/ 10 + X ] +10 = ( 10 xX + 10 { 10 + X} / 10 + X =( 100 + 20 x X)/ (10 + X)ohm

6/5 = 3/4

= 21/ 7 = 3

6/5 =3

( 100 + 20 x X )/ ( 10 +X) /5 = 3

100 + 20 x X = 15( 10+X)

20 xX - 15xX = 150 - 100

5 x X = 50

X = 10 ohm.

R equivalent1 = 5 + 15= 20ohm

R2 = 7 + 21 = 28 ohm

R = ( 20 x 28 ) / 48 = 280 /24 = 140 /12 = 70/6= 35/3 = 11.66ohm