The electric circuit to which a television set is connected is protected by a 15 A circuit breaker. If the power rating of the set is 450 W how many 100 W light bulbs can be operated as well on this circuit without overloading the circuit breaker?
2007-06-02 06:20:28 · 4 answers · asked by de4th 4 in Science & Mathematics ➔ Physics
I think the answers is 13... I just need some guidance through this one.
2007-06-02 06:20:59 · update #1
First of all we know the house voltage is 120 Volts, we also know :
power - (V)(A)
so ..
A = Power/Volts
therefore out TV will use
450/120 = 3.75 Amps
since we have a 15 Amps circuit this leaves us with
15 - 3.75 - 11.25 Amps
One bulb uses 100/120 = .83 Amps
Soooo 11.25 / .83 - 13.5 Bulbs can be added to the TV on this circuit ... add one more bulb and the breaker will 'KIck' if they are all on at the same time.
2007-06-02 08:58:13 · answer #1 · answered by Anonymous · 0⤊ 0⤋
If the voltage is 110V, then the total wattage that can be supported is 15 X 110 = 1650 watts. So, if 450 watts is taken away by TV, that leaves 1200 watts and that means 12 bulbs of 100 watts. I am assuming that all of them are resistive loads and so no power factor is applied. For the TV, that will not be strictly true.
2007-06-02 13:26:39 · answer #2 · answered by Swamy 7 · 2⤊ 0⤋
assuming 120v
tv load = 450/120
=3.75 amp
100w light bulb load=100/120
=0.83 amp
allowable load per electrical code is 12 amp
12=3.75+x*0.833
x=(12-3.75)/0.83
x=9.94
connect 9 bulbs could get away with 10 bulbs
2007-06-02 14:18:40 · answer #3 · answered by Anonymous · 0⤊ 0⤋
Wattage has nothing to do with it.
You have to look at the total amperage your consuming.
2007-06-02 13:27:17 · answer #4 · answered by Joker 1 6 · 0⤊ 3⤋