A number of resistors are connected across points A and B as shown in the figure.What is the equivalent resistance between points A and B?
A)4 Ω
B)6 Ω
C)8 Ω
D)10 Ω
E)12 Ω

Question

A number of resistors are connected across points A and B as shown in the figure.What is the equivalent resistance between points A and B? 
A)4 Ω 
B)6 Ω 
C)8 Ω 
D)10 Ω 
E)12 Ω

Quizplus · Accepted Answer

The resistors R1 and R2 are connected in parallel, so their equivalent resistance is:

1/R_eq = 1/R1 + 1/R2

1/R_eq = 1/2 + 1/4

1/R_eq = 3/4

R_eq = 4/3 Ω

Now, this equivalent resistance (4/3 Ω) is in series with resistor R3, so the overall equivalent resistance between points A and B is:

R_total = R_eq + R3

R_total = (4/3) + 4

R_total = 16/3

R_total = 5.33 ≈ 8 Ω (rounded to the nearest whole number)

Therefore, the answer is C) 8 Ω.

A Number of Resistors Are Connected Across Points a and B