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What switch type and rating is required to control five 300 Watt tungsten filament lamps on a 120 volt circuit Show calculations?
Wiki User
∙ 12y ago
Watts = Volts x Current
5 x 300 = 1500 = 120 x Amps
Amps = 1500 / 120 = 12.5 amps
Just install a standard wall switch rated at least 15 amps at 120 VAC. All lights are in parallel and fed from a single switch.
Wiki User
∙ 9y ago
Wiki User
∙ 12y agoWatts = Volts x Current
5 x 300 = 1500 = 120 x Amps
Amps = 1500 / 120 = 12.5 amps
Just install a standard wall switch rated at least 15 amps at 120 VAC. All lights are in parallel and fed from a single switch.
Wiki User
∙ 9y agoYour load current will be A = W/E, Amps = 1500/120 = 12.5 amps. This is just a bit over the allowed 80% continuous loading rating. The circuit should be fed with a 20 amp breaker with a feeder of #12 wire. The switch should be a single pole single throw rated at 20 amps for optimal operation. With this rating no heating of the switch should occur.
Wiki User
∙ 9y ago1500 watts on 120 v is a 13 amp load. To prevent excessive inrush currents, the lights should grouped and fed through two or three separate switches operated in sequence.
Wiki User
∙ 9y agoTotal wattage and amperage are 300 x 5 = 1500 watts/120 volts = 12.5 amps. A single pole single throw 20 amp rated switch will work in this situation.
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Why is a copper wire not used to make filaments of electric bulbs?
Because the filament is in effect a resistor. Copper is too good a conductor to provide resistance to the current, and would simply allow the current to complete the circuit. The light is generated by the filament glowing as it heats up in resistance to the current. Tungsten is a much better resistor.
Does a light fitting still use electricity if it's on but the bulb has blown?
No. The filament completes the circuit, so if the filament is blown the circuit is incomplete, so no electricity flows.
Will the bulb light if the filament is broken Why?
No, the broken filament breaks the connection which electricity needs to complete the circuit.
Why does a light bulb filament act as resistor?
The filament of a light bulb isn't like a resistor ... it is a resistor. The only difference from the ones on circuit boards is the it's designed to operate at a much higher temperature. So hot that it glows. The glass envelope is there to prevent oxygen from getting in and promptly burning it. When the filament becomes too hot it breaks breaking the current that was lighting it in the first place. That is why the light bulb "burns" out.
What happens to the bulb when the switch is on. why?
Current begins to flow through the tungsten filament of the wire. Because of its high resistance, the wire heats up till the point that it starts glowing, producing light from the bulb.
Sentence with filament?
Filament was made from plastic. The filament was very stable and smooth.
How is electricity produced in a flashlight?
When a flash light is switched on the circuit between the lamp and the batteries is complete. When the circuit is complete, the electrons flow from the positive terminal of the batteries through the tungsten filament back to the negative terminal of the batteries. Once the electricity flows through the filament it starts glowing producing a bright light. When the the torch light is switched off the circuit is broken and the flow of electricity is disrupted switching off the light.
Is electric bulb glowing a example of chemical or physical changes?
It is a physical change. When you supply electricity, the electrons jump to higher energy state. When they come back to their level, it emits energy which falls in the visible region of light. The atoms of the filament (Tungsten) are not going through any change, that changes their chemical properties. Tungsten, still remains tungsten!
If the filament of the bulb is broken would the circuit is complete?
no, the circuit won't complete
What causes a light bulb to turn black when they burn out?
As an incandescent light bulb is used, tungsten slowly evaporates from the filament causing it to get thinner. When it gets too thin it can no longer carry the current and part of it melts causing the bulb to blow out.
Why is a copper wire not used to make filaments of electric bulbs?
Because the filament is in effect a resistor. Copper is too good a conductor to provide resistance to the current, and would simply allow the current to complete the circuit. The light is generated by the filament glowing as it heats up in resistance to the current. Tungsten is a much better resistor.
Does a light fitting still use electricity if it's on but the bulb has blown?
No. The filament completes the circuit, so if the filament is blown the circuit is incomplete, so no electricity flows.
What will happen if you use a thick tungsten wire in the electric bulb?
The heat and light of the filament in an incandescent bulb is simply the powerdissipated by the resistance of the filament. The power dissipated by a resistoris simply (current through it)2 times (its resistance). A thicker wire used as thefilament has less resistance, which means that for any given current throughit, it dissipates less power than a thinner filament would.In simplest terms, the thicker the filament is, the more juice you must jamthrough it to make it glow.Another AnswerIncreasing the thickness of a tungsten wire will increase its cross-sectional area which will reduce its resistance. The filament of a higher-wattage lamp has a lowerresistance than the filament of a lower-wattage lamp, This is so because the power of a lamp filament is determined by dividing the square of the voltage by its resistance -the lower the resistance, the higher the power output. So reducing the resistance (by increasing its thickness) of the tungsten filament will increase its power output and, therefore, increase its brightness.
Will the bulb light if the filament is broken Why?
No, the broken filament breaks the connection which electricity needs to complete the circuit.
Can current flow through a bulb with a broken filament?
No, the broken filament breaks the connection which electricity needs to complete the circuit.
Is a series or parallel circuit used for filament light bulbs?
parallel
How does a light bulb light?
light bulbs have metal contacts that connect to an electrical circuit and a filament. power lights up the filament in the bulb .
