Three resistors with resistances of 2.0 Ω,6.0 Ω,and 12 Ω are connected across an ideal dc voltage source V as shown in the figure.If the total current through the circuit is I = 2.0 A,what is the applied voltage V?
A)6.0 V
B)3.0 V
C)2.0 V
D)2.7 V
E)1.5 V

Question

Three resistors with resistances of 2.0 Ω,6.0 Ω,and 12 Ω are connected across an ideal dc voltage source V as shown in the figure.If the total current through the circuit is I = 2.0 A,what is the applied voltage V? 
A)6.0 V 
B)3.0 V 
C)2.0 V 
D)2.7 V 
E)1.5 V

Quizplus · Accepted Answer

Using Ohm's Law, we can calculate the voltage drop across each resistor:

V1 = IR1 = (2.0 A)(2.0 Ω) = 4.0 V
V2 = IR2 = (2.0 A)(6.0 Ω) = 12.0 V
V3 = IR3 = (2.0 A)(12 Ω) = 24.0 V

The total voltage V applied to the circuit is equal to the sum of these individual voltage drops:

V = V1 + V2 + V3 = 4.0 V + 12.0 V + 24.0 V = 40.0 V

Therefore, the answer is:

D) 2.7 V

Three Resistors with Resistances of 2