Engineering Board Exam Reviewer · Ohm's Law · hard
A lamp has a hot resistance of 240, and a cold resistance of 20, . It is switched on at 120 V. How many times larger is the initial (cold) current than the steady (hot) current?
- 6 times
- 2 times
- 12 times
- 20 times
Answer
C. 12 times
Solution
Initial current =120/20=6 A and steady current =120/240=0.5 A. The ratio is 6/0.5=12.
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