In the following circuit R111 Ohm R24 38 Ohm R34 38 Ohm R42

In the following circuit, R1=11 Ohm, R2=4* 3.8 Ohm, R3=4* 3.8 Ohm, R4=2* 3.8 Ohm, R5=11 Ohm and E= 11 Volt. Calculate the current in R5 resistor. [Picture File-Ohm-2.jpg]

Solution

R1 = 11 ohm

R2 = 4(3.8 ohm) = 15.2 ohm

R3 = 4(3.8 ohm) = 15.2 ohm

R4 = 2(3.8 ohm) = 7.6 ohm

R5 = 11 ohm

R2 ,R3 ,R4 are in parallel.

Let the resultant of these three resistors be R then,

(1/R)=(1/R2)+(1/R3)+(1/R4)

       = (1/15.2)+(1/15.2)+(1/7.6)

      = 0.263

R = 3.8 ohm

R1,R,R5 are in series.

So, equivalent resistance Req = R1+R+R5

                                           = 16.5 ohm + 3.8 ohm+16.5 ohm

                                           = 36.8 ohm

Current in the circuit i = E /Req

                                = 11/36.8

                                = 0.2989 A

Current in R5 resistor = 0.2989A