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Question
5 identical resistors are connected in parallel to a battery. If the current of 15A flows from the battery, how much current flows through any one of the resistors?

a. 3A  b.5A  c.15A  d.2A  e. 1A

Is this really just a question where I do 15A / 5 and get 3?

Answer
Hello Sona,

Yes, you are right. The current is a flow of electrons. When the 15A current reaches the parallel network, because the resistors are equal, the current divides equally into 5 smaller currents.

If a river had an island in the middle, the current of water would divide in 2 branches. The sum of the 2 branches would be current equivalent to the current before the island was reached.

Each electron making up the current flows through only one of the resistors. Each resistor would have the same number of electrons pass through them per second. That number of electrons per second in an individual resistor would be 1/5th of the current that leaves the battery. Then after passing through the resistors, the smaller individual currents re-unite to form a 15 amp current returning to the battery.

Since the sum of the 5 equal individual currents has to be 15 A when the 5 re-unite, each individual current going through a resistor must be 3 amps.

I hope this helps,
Steve

Physics

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Steve Johnson

Expertise

I would be delighted to help with questions up through the first year of college Physics. Particularly Electricity, Electronics and Newtonian Mechanics (motion, acceleration etc.). I decline questions on relativity and Atomic Physics. I also could discuss the Space Shuttle and space flight in general.

Experience

I have a BS in Physics and an MS in Electrical Engineering. I am retired now. My professional career was in Electrical Engineering with considerable time spent working with accelerometers, gyroscopes and flight dynamics (Physics related topics) while working on the Space Shuttle. I gave formal classroom lessons to technical co-workers periodically over a several year period.

Education/Credentials
BS Physics, North Dakota State University
MS Electrical Engineering, North Dakota State University

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