Question

A resistance r is connected in series with a parallel circuit comprising of two resistors 12 and 8. The total power dissipated is 100w, when a voltage of 12 v is applied. Interpret the value of resistance r

Answer 1

Answer:

v=ir and i=v/r

w=vi so w=v*v/r

so r=v*v/w

Explanation:

r=12*12/100

r=144/100

r=1.44 ohms ANSWER

Answer 2

Answer:

r = 118.56 .ohm

Explanation:

since, r is connected in series with the parallel combination  of 12 and 8.

so, the equivalent resistance will be

     R=  24/5 + r

here, v= 12V

total current flowing through the circuit is

       I = v/R

       I = 12* 24+5r / 5

       I = 60/ 24+5r  --------1

P= 100W

 I = P/v

 I = 100/12   ----2

from 1 and 2

 r = 118.56 ohm