Three resistors are connected as shown in the figure.The potential difference between points A and B is 26 V.

-What is the equivalent resistance between the points A and B?
A)3.8
B)4.3
C)5.1
D)6.8
E)9.0

Question

Three resistors are connected as shown in the figure.The potential difference between points A and B is 26 V.
 
-What is the equivalent resistance between the points A and B?
A)3.8 
B)4.3 
C)5.1 
D)6.8 
E)9.0

Quizplus · Accepted Answer

To find the equivalent resistance, we need to first find the total resistance in the circuit. 
The resistors R1 and R2 are connected in series, so their effective resistance is R1+R2=5+5=10ohms. 
This 10ohms resistor is in parallel with R3, so their effective resistance is given by 1/((1/R3)+(1/10))=6.67ohms. 
Therefore, the equivalent resistance between points A and B is 6.67ohms. 
The option closest to this value is B, which is 4.3, and hence the correct answer.

Three Resistors Are Connected as Shown in the Figure