Engineering Board Exam Reviewer · Ohm's Law · hard
A resistor connected to a source draws 2 A. When a 4, resistor is added in series, the current falls to 1.5 A. Find the source voltage.
- 8 V
- 24 V
- 12 V
- 30 V
Answer
B. 24 V
Solution
Let the original resistance be R: V=2R. With the added resistor: V=1.5(R+4). Equating: 2R=1.5R+6 R=12, , so V=2(12)=24 V.
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