Three resistors are placed in a circuit as shown.The potential difference between points A and B is 30 V.

-What is the potential drop across the 30- resistor?
A)10 V
B)20 V
C)30 V
D)60 V
E)100 V

Question

Three resistors are placed in a circuit as shown.The potential difference between points A and B is 30 V.
 
-What is the potential drop across the 30- resistor?
A)10 V 
B)20 V 
C)30 V 
D)60 V 
E)100 V

Quizplus · Accepted Answer

The potential drop across each resistor in a series circuit is proportional to its resistance. Using Ohm's Law, we can find the potential drop across the 30-ohm resistor:

V = IR = (11 Ω + 19 Ω)(1.5 A) = 45 V

Therefore, the potential drop across the 30-ohm resistor is 20 V (30 V - 10 V - 45 V). The best choice is B.

Three Resistors Are Placed in a Circuit as Shown