Question

the series combinations of two 10ohm resistance is parallel combinations with a 20ohm resistance. Determine the equivalent resistance of the final​

Answer 1

Answer:

Resistance seen from power supply is R1= 20/1.5=13.333 ohms

Substracting 10 ohms resistor in serie R1-10= 3.333 ohms=Rp or parallels resistance.

the two 15 ohms in parallel gaves half resistance 7.5 ohms

Rp=7.5*R / (7.5+R) or (7.5+R)*Rp=7.5*R solving for R

7.5 *Rp=R*(7.5-Rp) or R=7.5*Rp/(7.5-Rp) replacing Rp=10/3

R=75/(22.5-10)=75/12.5=6 ohms