Three resistors are placed in a circuit as shown. The potential difference between points A and B is 30 V.
-What is the equivalent resistance between the points A and B?
A)10 $\varOmega$
B)20 $\varOmega$
C)30 $\varOmega$
D)50 $\varOmega$
E)100 $\varOmega$

Question

Three resistors are placed in a circuit as shown. The potential difference between points A and B is 30 V. 
-What is the equivalent resistance between the points A and B?
A)10 $\varOmega$ 
B)20 $\varOmega$ 
C)30 $\varOmega$ 
D)50 $\varOmega$ 
E)100 $\varOmega$

Quizplus · Accepted Answer

To find the equivalent resistance, we need to find the total resistance of the circuit. The resistors R1 and R2 are in parallel so their equivalent resistance is:

1/Req = 1/R1 + 1/R2 
1/Req = 1/6 Ω + 1/6 Ω 
1/Req = 2/6 Ω 
Req = 3 Ω

The resistor R3 is in series with the equivalent resistance of R1 and R2. Therefore, the total resistance is:

Rtotal = Req + R3 
Rtotal = 3 Ω + 27 Ω 
Rtotal = 30 Ω

Hence, the correct answer is C) 30 Ω.

Three Resistors Are Placed in a Circuit as Shown Ω\varOmegaΩ B)20 Ω\varOmegaΩ

Three Resistors Are Placed in a Circuit as Shown $\varOmega$ B)20 $\varOmega$