# Power Dissipation

Discussion in 'Homework Help' started by tjjam2003, Apr 7, 2006.

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1. ### tjjam2003 Thread Starter Member

Apr 5, 2006
22
0
If a resistor of 350 ohms is connected across a source of 175 volts, with a current of 0.05 amps what is the power dissipation?? It should be 87.50W right??

What if the voltage is reduced to 105 volts, what is the power being dissipated by the resistor??

The answer in the book says : 31.5W

I'm not sure how they got that answer, how do I write it out to get the answer??

Thanks !!!

2. ### Papabravo Expert

Feb 24, 2006
10,340
1,850
You must have been typing a bit fast. 175 volts on 350 ohms is 0.5 amperes, not 0.05 and yes that woul be 87.5 Watts. A substantial power resistor!

Twinkle twinkle little star
Power's equal I squared R
Code ( (Unknown Language)):
1.
2. I = E/R implies 105/350 = 0.3 Amperes
3.
4. (0.3)*(0.3)*350 = 31.5 Watts
5.
6. Also
7.
8. P = E^2/R = ((105)*(105))/350 = 31.5
9.
What kind of book gives you a problem, and does not show you how they got the answer? May be time for a new book!

Mar 8, 2006
80
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4. ### tjjam2003 Thread Starter Member

Apr 5, 2006
22
0
Thanks...I'm sure I'll be back with another one.

5. ### Papabravo Expert

Feb 24, 2006
10,340
1,850
Gee paultwang,

You could have left your answer up, after all you went to the trouble of creating it, and a second opinion or viewpoint never ever hurts.

cheers

6. ### bk123 New Member

Nov 24, 2014
5
0
If a 10 ohm resistance is connected to an a.c voltage of 100 sin(314t + 30deg), the power dissipated is?

Apr 5, 2008
15,806
2,390
Hello,

Bertus

PS closed due to old age