MCAT Question A Day - 2/23/14 - Answer!
A 20 Ohm and a 40 Ohm resistor are connected in series with a voltage source as shown below.
If the current through the 20 Ohm resistor is 2.0 A, what is the voltage drop across the 40 Ohm resistor?
A. 40 V
B. 80 V
C. 120 V
D. 400 V
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The correct answer is (B). Because the resistors are in series, the same current must flow through both resistors. Apply Ohm’s law to find the voltage across the 40 Ohm resistor.
V = IR = (2.0 A) (40 Ohm) = 80 V
