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burgess

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Registered: 2014-06-26

Posts: 49

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A problem on heat production

Help me to solve my physics homework problem

What is the amount of heat produced, when 3 resistors of 45 ohm are connecting in a series circuit with a 50-V source?

Maburo

Member

From: Alberta, Canada

Registered: 2013-01-08

Posts: 287

Re: A problem on heat production

The resistors are in series, so their equivalent resistance is simply the sum of the three resistances,

When current is flowing through a resistor, electrical energy is converted into thermal energy at the rate

In our case, we are looking at the heat produced over all resistors, in series, so we can write

Then we simply plug in our numbers:

Remember, this is power - the rate at which the energy is being converted. So if we want to look at heat, we can say that 18.52 Joules of heat are being produced every second that current is running through the resistors. For example, if you left the circuit connected for 10 seconds, 185.2 Joules of enerygy would be dissipated.

Does this make sense?

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"Pure mathematics is, in its way, the poetry of logical ideas."
-Albert Einstein