Question

class 10 selection paper, solve plZ,,,

Answer 1

Equivalent resistance is 4 .

4 ohms and 8 ohms are in series .

R = 4 + 8 = 12

x and 5 ohms are in series .

R = x + 5 .

Now x + 5 and 12 are in parallel.

1 / ( x + 5 ) + 1 / 12 = 1 Re

= > 1 / ( x + 5 ) + 1 / 12 = 1 / 4

= > 1 / ( x + 5 ) = 1 / 4 - 1 / 12

= > 1 / ( x + 5 ) = ( 3 - 1 ) / 12

= > 1 / ( x + 5 ) = 2 / 12

= > 1 / ( x + 5 ) = 1 / 6

= > x + 5 = 6

= > x = 6 - 5 = 1

Value of x is 1.

Answer 2

R" = 4+8= 12
R' = 5+x

1/R" + 1/R' = 1/12 + 1/5+x

so

1/R = 17+x/60+12x
1/4= 17+x/60+12x
8x= 8
so x = 1