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When a light bulb is rated 100 w for 220 v supply. what is the resistance of the bulb and the peak voltage of the sources?
Wiki User
∙ 12y ago
Ohm's Law: Resistance is voltage divided by current
Power Law: Power is current times voltage
Combining them gives: Resistance is voltage squared divided by power
220 volts squared divided by 100 watts = 484 ohms. Note that this is hot resistance. If you measure the bulb in the cold state, you will get an entirely different, smaller, value, due to the extreme temperature coefficient of the filament.
Independently of that, since you ask for peak voltage, that means you are talking about an AC voltage source. We have to assume a sinusoidal waveform, and that the 220 volts was the RMS value. In this case, the peak value is simply the RMS value multiplied by the square root of 2, i.e. 0.707..., making the peak value 311 volts.
Wiki User
∙ 12y ago
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What is the current being drawn by a 100W light bulb and what is the resistance of a 100W light bulb?
Assume the rating of 100W refers to operation on a supply of 117 volts.Power = (voltage) x (current)Current = (power) / (voltage) = 100/117 = 0.855 ampere (rounded)Power = (voltage)2 / (resistance)Resistance = (voltage)2 / (power) = (117)2 / 100 = 136.89 ohms
What voltage is required to sustain a current of 0.50 through a light bulb resistance of 190?
The voltage of a circuit with a resistance of 250 ohms and a current of 0.95 amps is 237.5 volts. Ohms's law: Voltage = Current times Resistance
Is tube light run without choke?
No it will not. If you need increase the supply voltage and remove the choke.
What will happen to the resistance and the brightness if you add a light bulb to the circuit?
If a rheostat is connected in parallel with a light bulb, the setting of the rheostat should have no effect on the performance of the light bulb, as long as the power supply is able to maintain its output voltage and deliver the current demanded by their parallel combination.
What is the relationship between lamp brightness and resistance in a series circuit?
The higher the resistance the dimmer the light will become. The voltage drop (current) is proportional to the resistance as seen in the equation V=IR, since voltage remains the same throughout a series circuit if the equivalent resistance goes up the amount of current reaching the lightbulb must go down to equal the voltage thus creating a dimmer lightbulb.
What is the current being drawn by a 100W light bulb and what is the resistance of a 100W light bulb?
Assume the rating of 100W refers to operation on a supply of 117 volts.Power = (voltage) x (current)Current = (power) / (voltage) = 100/117 = 0.855 ampere (rounded)Power = (voltage)2 / (resistance)Resistance = (voltage)2 / (power) = (117)2 / 100 = 136.89 ohms
When the bulb is the resistance what this tells about the resistance?
An incandescent bulb has a filament that has a resistance. The value of the resistance determines the current that will flow for a given supply voltage. The heat generated by the current flowing through the filament gives off light. As the resistance of the filament decreases the current increases and you get more light.
In what way the connections are made to get a higher output current from light?
A light doesn't output current, it "draws" current based on voltage and its resistance. Voltage = Current x Resistance or Current = Voltage / Resistance. (Ohm's Law)
Why is there zero current when a light bulb out?
there is no voltage and resistance
Why is there zero current when a light bulb burns out?
there is no voltage and resistance
What voltage is required to sustain a current of 0.50 through a light bulb resistance of 190?
The voltage of a circuit with a resistance of 250 ohms and a current of 0.95 amps is 237.5 volts. Ohms's law: Voltage = Current times Resistance
Is tube light run without choke?
No it will not. If you need increase the supply voltage and remove the choke.
What will happen to the resistance and the brightness if you add a light bulb to the circuit?
If a rheostat is connected in parallel with a light bulb, the setting of the rheostat should have no effect on the performance of the light bulb, as long as the power supply is able to maintain its output voltage and deliver the current demanded by their parallel combination.
Why does the voltage drop as electricity flows through a light bulb?
Do you mean why is the voltage in a circuit lower after the light bulb than before it? If so, it's because the light bulb filament has electrical resistance. When an electrical current flows through a resistance, there is a voltage drop across the resistance (Ohm's law).More fundamentally, the light bulb is producing light, which is a form of energy. The voltage drop across the light bulb comes from the fact that electrical energy is being turned into light. If voltage didn't drop, you would be producing energy from nothing. Furthermore, if there were no voltage drop, your circuit would behave the same whether you had no light bulbs, one light bulb, or eighteen million light bulbs - something that clearly can't be the case.
What will happen if this 4.5 v bulb is connected to a 1.5 v cell?
The bulb need the correct voltage to operate. Your bulb would light if it is a 1.5 volt light. So the voltage of the supply and the light must be matched. Too little voltage won't light the light, too much will light it too much and blow it up.
Is it sensible for the TV to be connected in series with the light bulbs?
Connecting light bulb is equivalent to connecting a resistance. If you have connected light bulb, there will be some voltage drop across it and your TV may not get sufficient voltage. However if resistance is not big enough, than it wont have any effect.
In a series circuit when adding light bulbs does the current change?
Yes. The current is inversely proportional to the resistance. I = V / R where I is current, V is voltage, and R is resistance. Adding light bulbs adds resistance. Current is constant throughout a series circuit; it doesn't change no matter what. Voltage changes.
