Question

A resistance R is connected in series with a parallel circuit of 12Ω and 8Ω.Total power dissipated is 70W when the applied voltage is 20V. Apply the basic laws and find the value of R.

Answer 1

Answer:

Power across 4Ohm= V244=36W

So, V4=12V

Since 4 and 6 Ohm are parallel, so

Req.=2.4 Ohm

As 4 and 6 Ohm are parallel, the voltage across them is same=12V. So, current through parallel circuit

I=122.4=5A

As this circuit is in series with R, so same current flows through R i.e, 5A.

Potential difference across R is (15–12)=3V as parallel branch has 12V and source is 15V.

So, R=15–125=0.6Ω