Answer to Question #117439 in Electric Circuits for Cecilia LeBrun

Question

I have a parallel circuit attached to a simple circuit. The parallel circuit resistors are 20 ohms and R2 is unknown I2 is unknown. In the simple circuit there is a resistor with 24 ohms and 4 V and the total Volts are 6V. What are the values for R2 and I2?

Answer 1

$I=\frac{V_{cd}}{R_3}\approx0.17A, V_{ab}=V-V_{cd}=2V,$ hence $I_1=V_{ab}/R_1=0.1A$ hence

$I_2=I-I_1=0.07A$ hense $R_2=V_1/I_2\approx29ohms$

where $R_1=20ohms,R_3=24ohms, V_{cd}=4V,V=6V$