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According to ohms law what is the resistance of a light if the voltage is 9.0 volts and the current is 0.30 amps?
Wiki User
∙ 11y ago
30 ohms
AnswerAn incandescent lamp doesn't obey Ohm's Law, because the ratio of voltage to current changes as the supply voltage is varied. All you can say is that, when the applied voltage is 9.0 V, then the resistance will happen to be 30 ohms. If you change the applied voltage to some other value, then you will find the resistance will have changed too.Ohm's Law isn't a universal law; in fact, most materials and circuit devices do not obey Ohm's Law, and tungsten, from which lamp filaments are manufactured, is an example of a metal that does not obey Ohm's Law (we call them 'non-linear' or 'non-ohmic')
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∙ 11y ago
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What part of a light bulb has the most resistance?
the actual filament itself in a light bulb has the most resistance,this is why it glows and produces light,the rest of the bulb is sufficiently engineered to carry the voltage and current applied to it without producing too much heat.
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.
When the resistance in a circuit increases what happens to the current flow?
"Ohms Law" defines resistance (R) as the the ratio of voltage (V) to current (I).R = V/IIf you move those variables around, you can get the formula:I = V/RSo you can see that when resistance increases, current flow will decrease.CommentResistance is most definitely not defined as 'the ratio of voltage to current', although that ratio may tell you what it happens to be.Resistance isn't a variable in the Ohm's Law equation. It is a constant because it is unaffected by either current or resistance.
What effect does decreased resistance have on a circuit?
resistance is the opposition to the flow of an electric current, therefore the current will decrease as the resistance increases. Resistance also creates heat. This is how the light globes in a circuit light up.
The devices thgat do not follow ohms law?
All devices follow Ohm's law. Ohm's law states that voltage is equal to current times resistance. This is always true. DC, AC, RF, whatever. Resistance, capacitance, or inductance, whatever. Its a matter of proper perspective, and its a matter of taking everything into account.Some devices do not have a linear response to voltage or current.Take the light bulb, for instance. If you measures its resistance you can calculate what you think its current and power would be at a certain voltage, and you would be wrong, unless you also considered temperature. This is because light bulbs have a very dramatic resistance to temperature coefficient. As an example, a 40W applicance bulb might have a cold resistance of 27 ohms. That translates to 4.4A or 533W, with a 120V source. The truth is that the 40W bulb has a hot resistance of 360 ohms, giving an on current of 0.333A and an on power of 40W, with a 120V source.For another example, look at the diode. Initially, it appears to have high resistance. When the voltage across it reachs the forward bias voltage (or the reverse bias voltage for a zener diode) it starts to conduct and draw current. As you increase the current, you note that the voltage is relatively constant. That is certainly not a resistor - the diode's resistance is increasing as current increases so as to make the voltage be somewhat constant. You can still calculate voltage, current, resistance, and power, but only at each point of observation.For the last example, though not really an example of non-linear resistance, consider the capacitor. In a DC circuit, the capacitor initially has zero ohms resistance, but it quickly rises to infinity ohms depending on current and capacitance. In an AC circuit, this a much more interesting and useful case - the capacitor stabilizes at a certain capacitive reactance, and the operation of the curcuit complies with Ohm's law, but lo and behold - you find that the current is no longer in phase with the voltage. While this complicates calculations, nothing changes the fact that voltage is current times resistance. That is an immutable given - your task is to learn how to measure it correctly.In each of these cases, and in any other case, Ohm's law applies, but it applies in a certain way, under a certain set of circumstances. The bulb has 360 ohms of resistance at 120V, giving 0.333A and 40W. That is very clear. What you must maintain equally clear is that resistance is not always a constant - and you must consider that inconstancy every time you change the conditions of the circuit.AnswerOhm's 'Law' is somewhat of a misnomer, because it is not really a universal law because it only applies to a small range of conductors. Ohm's Law only applies when the ratio of voltage to current is constant for variations in voltage. Devices that follow Ohm's Law are called linear or ohmic; those that don't are called non-linear or non-ohmic. Most metal conductors are linear, but some are not. For example, tungsten does not obey Ohm's Law because its ratio of voltage to current changes as the voltage applied across it changes -in other words, tungsten is non-linear. Electronic devices, such as diodes, electrolytes, and gases are all non-linear and do not obey Ohm's Law.Having said that, the ratio of voltage to current will always tell you what the resistance of a device happens to be for that particular ratio and, so, the equation R = V/I applies to all devices whether they are linear or non-linear. However, this equation is not derived from Ohm's Law, but from the definition of resistance.
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
If the voltage is increased and current remains the same, what happens to the resistance?
According to ohms law (R=V/I) if voltage increases the resistance also increases .For example: If voltage (V) becomes 2 times the resistance (R) also increases becomes 2 times keeping the current (I) same
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.
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 is the current if the light bubs are in paralles?
The current if the light bulbs are parallel is I= V/R where V is the voltage and R is the resistance of the bulb.
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.
What would happen to the current in a simple circuit if a bulb with a higher resistance were used?
Ohm's law applies: Current = Voltage / Resistance As such if you double the resistance of the light bulb you end up with half as much current.
What is the current through each light bulb in a series circuit?
it remains same i=voltage/total resistance
A light bulb has a resistance of 5 ohms and a maximum current of 10 A. How much voltage can be applied before the bulb will break?
50-Voltage
