The figure below shows a circuit consisting of five resistors and one battery. T

ID: 2294491 • Letter: T

Question

The figure below shows a circuit consisting of five resistors and one battery. The battery has an emf of 13.0 V, and the value of R is 4.00 ohms.

(a) The equivalent resistance of the circuit is

**For this problem, I got 20 ohms, but the answer is 4.8 ohms. I don't understand this.

Steps I took to solve this:

1) Rc and Rd are in a series circuit so I added them.

2) Rb and Rcd are in a parallel circuit so I did 1 / [ (1/Rcd) + (1/Rb) ]
3) Ra, Re, and Rbcd are in a series circuit so I added them.

Thus I got 20 ohms, but why is this wrong?

Rc and Rd are in series s0 Rc +Rd = 6R

(Rc +Rd) and Rb are in parrallel so . R' = (Rc +Rd) x Rb / (Rc +Rd+Rb) = 6R x 3R / 9R = 2R

now R'(2R) and Re in series

so 2R +R = 3R

and 3R and Ra are in parralel

so Rnet = 3R x 2R / 5R = 6R /5

so rnet = 4.8 ohm

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