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Why the slope of voltage-resistance characteristic increases in the case of tungsten lamp and decresing in case of carbon lamp?
If the filament really was made from a material that has a negative temperature coefficient (as temperature increases, resistance decreases) then the decreasing resistance would cause more and more current to be taken as the lamp heated up and the temperature would get higher and higher in a runaway manner until either the power supply's breaker would trip or (more likely) the light bulb's filament would simply burn open.
In fact the filament has to be made from a material that has a positive temperature coefficient. (As temperature increases, resistance increases.) Then, as the bulb's temperature rises, its filament's increasing resistance causes less current to be taken than when it was cold. Quite quickly a stable "steady-state" temperature and "running" resistance is reached so that the bulb simply continues to give out a steady amount of light according to the current it is taking from the electricity supply.
What else can I help you with?
What is the target material used in linear accelerator?
Tungsten. Gold or uranium may also be used but it is usually tungsten.
What is the source material in portable x-ray machine?
tungsten block
Is ohms law applicable to filament?
Absolutely not! A tungsten filament is an example of a non-linear or non-ohmic material, and it does not obey Ohm's Law. Ohm's Law is a law of constant proportionality; in other words, for it to apply, the ratio of voltage to current must be constant over a wide range of voltages. Increasing the voltage of a tungsten filament to its rated voltage causes its resistance to increase around 15 - 18 times, compared with its 'cold' resistance. Therefore, the ratio of voltage to current changes significantly as the applied voltage changes -so it does not obey Ohm's Law.However, the ratio of voltage to current will always tell you what the resistance happens to be for any particular ratio. Since, for tungsten, because the ratio increases as the voltage increase, the resistance changes too.To summarise, for Ohm's Law to apply, there MUST be a linear relationship between voltage and current; with tungsten, the relationship is a curved line and, so, it is non-linear and does not obey Ohm's Law.
What is the material of the electrode in TIG Welding Process?
TIG welding uses tungsten electrodes. Some electrodes also contain Thorium some also contain Zirconiun some are pure Tungsten. Each has its own applications.
What is a concrete nail made of?
Concrete- I remember when concrete nails were made of a forged tungsten steel.
Why slope of VI characteristics is positive for tungsten lamp?
The slope of the voltage-current (VI) characteristics for a tungsten lamp is positive because as the current increases, the temperature of the tungsten filament rises, leading to an increase in resistance. This phenomenon is due to the positive temperature coefficient of resistance of tungsten, where the resistance increases with temperature. Consequently, the relationship between voltage and current becomes non-linear, resulting in a positive slope in the VI characteristics. This behavior is typical for incandescent lamps, where the filament's temperature significantly affects its electrical properties.
How do you identify Tungsten?
Tungsten is heavy and fragile . Pure tungsten metal should be in dark grey color, tungsten metal usually use in industrial for filament and making steel. Another important part for tungsten is the tungsten carbide, usually use in jewelry. Tungsten carbide jewelry are in bright silver color, it's made from the 85.7 tungsten carbide and together mixed titanium.
What metal is uncuttable?
No metal is completely uncuttable, but some metals like tungsten and titanium are very difficult to cut due to their high hardness and strength. These metals are often used in industrial and military applications where their resistance to cutting is a desirable characteristic.
Is tungsten tougher that tungsten carbide?
No. Tungsten is an element, where as tungsten carbide is an alloy, or a mixture of elements (tungsten, nickel, tantalum, niobium, titanium, and chromium). Tungsten carbide is much easier to work into styles and designs, but does not change the hardness of the metal.
Is tungsten magnetic?
Yes, tungsten is not magnetic. Tungsten is a diamagnetic material, which means it is slightly repelled by a magnetic field.
What is the molecular formula for tungsten?
The chemical symbol for Tungsten is W. (Tungsten is also known as Wolfram.)
What is ore of tungsten?
Tungsten is found in wolframite (hence why the Germans called tungsten wolfram).
What are the substances in tungsten?
There are none, tungsten is a pure element so it is made of only tungsten.
What is Tungsten original name?
Tungsten's original name is Wolfram that is why the symbol for Tungsten is a W
Is tungsten noxious?
In the environment tungsten: * acidifies soils * impacts soil microbial commnities * decreases bacterial species in soil * increases fungal types in soil * kills red worms and plants * enters the food chain
Could you give a motto with tungsten?
We should be strong as tungsten heavy alloy,tough as tungsten carbide.This is the motto of China Tungsten Online
Why does tungsten resistance change when it gets hotter?
The resistance of tungsten increases with temperature because as temperature rises, tungsten atoms vibrate with greater energy, impeding the flow of electrons. This increased vibration disrupts the flow of electrons, leading to a higher resistance in the material.
