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Voltage squared equals current times resistance, so voltage squared divided by power equals resistance. So, for a 60W bulb: * (120V)^2 / 60 = R * 14400 / 60 = 240 ohms Keep in mind this is after the bulb reaches operating temperature. The resistance of the filament is temperature dependent.
What else can I help you with?
Does ohm's law also apply to the filament lamp?
No. For Ohm's Law to apply, the ratio of voltage to current must remain constant for variations in voltage. This simply doesn't happen with a tungsten filament. In fact, MOST materials don't obey Ohm's Law.
If the tungsten filament of a lamp has a cross-sectional are of 5x10-9 m2 how long must it be have a resistance of 120 ohms at 20 degrees Celsius?
To find the length of the tungsten filament, you can use the formula: R = ρ * (L/A) Where R is the resistance (120 ohms), ρ is the resistivity of tungsten, A is the cross-sectional area (5x10^-9 m^2), and L is the length of the filament. Rearranging the formula to solve for L gives: L = R * A / ρ Given the resistivity of tungsten at 20 degrees Celsius, you can calculate the length of the filament.
Why is iodine sometimes introduced into a tungsten lamp?
Iodine is introduced into a tungsten lamp to combine with the tungsten vaporized from the filament and create a tungsten iodide compound. This compound prevents the tungsten from depositing back onto the filament, thus extending the lifespan of the lamp. It also helps to maintain a stable color temperature of the light emitted by the lamp.
Why does a bulb glow when electric passes through it?
The filament in the bulb has resistance. The current flowing through the resistance of bulb causes the filament to dissipate energy in the form of heat and light. The filament is actually glowing white-hot because of the energy it is dissipating, thus giving off light.
What is the thin wire inside a bulb called?
It is called a filament and usually made of tungsten steel.
Is resistance in the filament of a lamp essential or not?
Yes, the resistance of the filament of a light bulb is what generates enough heat to make the filament glow and produce light.
Graph of resistance of filament lamp against potential difference?
As potential difference increases in a filament lamp, resistance also increases due to an increase in temperature. The relationship between resistance and potential difference in a filament lamp is non-linear due to the temperature-dependent nature of resistance in the filament material. At low voltages, the resistance is relatively low, but as the temperature of the filament increases with higher voltages, the resistance also increases.
What is the nature of the slope of the viltage vs resistance in filament lamp?
The relationship between the voltage and resistance in a filament lamp is non-linear. As the voltage increases, the resistance in the filament of the lamp also increases due to the heating effect. This increase in resistance causes the current to increase at a slower rate than expected, leading to a non-linear slope in the voltage-resistance graph.
Does a lamp with a thick filament draw more current or less current than a lamp with a thin filament?
A lamp with a thick filament will draw more current. What restricts the current flow in the filament is the resistance of the filament which increases as the temperature of the filament increases. A thin filament requires less energy to get heated up that a thick one so less current to achieve threshold resistance. Also a thick filament provides a broader path for current so there is less resistance per increase in degree centigrade. For these two (closely related but distinct) reasons it will require more current for the filament to get heated up to threshold resistance.
Why is the filament inside an electric lamp made very fine?
The filament is fine so that its electrical resistance can be quite high. It is also long, for the same reason. Usually it is coiled up to fit the length in the lamp. The heating effect of electric current is proportional to the current squared, time the resistance (I*I*R). Most of the effect is due to the current. The current through the filament must be limited to stop it melting. Adding resistance will do that. Taking resistance away increases heating. So, a low energy lamp has a very thin filament and a high energy lamp will have a thicker filament.
Does a lamp with a thick filament draw more or less current than a lamp with a thin filament?
A lamp with a thick filament will draw more current. What restricts the current flow in the filament is the resistance of the filament which increases as the temperature of the filament increases. A thin filament requires less energy to get heated up that a thick one so less current to achieve threshold resistance. Also a thick filament provides a broader path for current so there is less resistance per increase in degree centigrade. For these two (closely related but distinct) reasons it will require more current for the filament to get heated up to threshold resistance.
Why is a filiament lamp a non ohmic conductor?
A filament lamp is a non-ohmic conductor because its resistance changes with applied voltage. As the voltage increases, the resistance also increases. This is due to the temperature-dependent behavior of the filament material, which causes the resistance to vary.
What is nonlinear resistance?
A nonlinear resistance is a resistance which is different for different voltages ie current is not proportional to voltage. An example of this is the filament of an incandescent lamp.
Why does the filament lamp does not follow Ohms Law give any example?
Well, honey, the filament lamp doesn't give a hoot about Ohm's Law because its resistance changes with temperature. As the current increases, the temperature of the filament rises, causing the resistance to also increase. It's like trying to control a wild horse - good luck getting it to follow any law!
Why does a filament lamp get hot when you use high voltage?
because there is a correlation between resistance and voltage and current. The equation resistance = voltage divided by current shows that the higher the voltage, the bigger the resistance,, and the bigger the resistance the hotter the filament lamp will get because of the electrons bumping into each other which means there is a loss of energy and that energy is being transferred to the filament making the actual filament bulb hot since there is more thermal energy wasted at the end.
WhY does a filament lamp get when you us high voltage?
because there is a correlation between resistance and voltage and current. The equation resistance = voltage divided by current shows that the higher the voltage, the bigger the resistance,, and the bigger the resistance the hotter the filament lamp will get because of the electrons bumping into each other which means there is a loss of energy and that energy is being transferred to the filament making the actual filament bulb hot since there is more thermal energy wasted at the end.
Why is there a curve and not a straight line in the graph for a filament lamp?
I had to answer this and found out that............ The line on the graph that represents the filament lamp is curved because the resistance of it increases with supplied voltage Hope this is alright for you :) x
