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Light bulbs

  • Thread starter tDexx
  • Start date
  • #1
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Homework Statement


A 220 volt circuit is fused for 30 amps. How many 60 watt incandescent soft whote light bulbs with tungsten filament burning at 3,0000 celsius can be used at the same time in the circuit without tripping the fuse?


Homework Equations


N/A

The Attempt at a Solution


(w/220)=30
220=30 amps(w)
220/30 amps=7.33 watts
 

Answers and Replies

  • #2
PeterO
Homework Helper
2,425
46

Homework Statement


A 220 volt circuit is fused for 30 amps. How many 60 watt incandescent soft whote light bulbs with tungsten filament burning at 3,0000 celsius can be used at the same time in the circuit without tripping the fuse?


Homework Equations


N/A

The Attempt at a Solution


(w/220)=30
220=30 amps(w)
220/30 amps=7.33 watts
At least have a look at this:

http://en.wikipedia.org/wiki/Power_(physics)

Go to the electric power section for some useful formulae. Those same formulae will be in your text book.
 
  • #3
6
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Unfortunately i don't have a textbook to go with my homework...
 
  • #4
PeterO
Homework Helper
2,425
46

Homework Statement


A 220 volt circuit is fused for 30 amps. How many 60 watt incandescent soft whote light bulbs with tungsten filament burning at 3,0000 celsius can be used at the same time in the circuit without tripping the fuse?


Homework Equations


N/A
In one of your other posts you listed P = IV. That would be really useful here.

The Attempt at a Solution


(w/220)=30
220=30 amps(w)
220/30 amps=7.33 watts
See above.
 

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