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How many volts are supplied to operate an indicator light on a DVD player that has a resistance of $140 \Omega$ , given that 25.0 mA passes through it?
Question by OpenStax is licensed under CC BY 4.0.
Final Answer

$3.50 \textrm{ V}$

Solution Video

OpenStax College Physics Solution, Chapter 20, Problem 21 (Problems & Exercises) (0:31)

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Video Transcript

This is College Physics Answers with Shaun Dychko. Begin by writing down the information we're given. We're told that the resistance in this DVD indicator light is 140 ohms and the current going through it is 25 milliamps which we convert into amps by multiplying by ten to the minus three because that's what the prefix milli means. So the voltage will be the current multiplied by resistance so 25 times ten to minus three amps multiplied by 149 ohms, gives three and a half volts.