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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?
Wiki User
∙ 10y ago
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.
Wiki User
∙ 10y ago
Wiki User
∙ 11y agofor Tungsten lamp the slope of the curve is positive where for carbon it is negative
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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.
When cathode rays strike a metal target say tungsten what happens?
x-rays are emitted
How do you identify Tungsten?
Tungsten is a hard, rare metal with a silvery-white color that is commonly used in industry due to its high melting point and density. It can be identified by its high density, resistance to corrosion, and ability to produce a characteristic spark when struck against a hard surface. Tungsten is also often marked with the letter "W" on products as it's chemical symbol.
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.)
Is tungsten noxious?
Tungsten is considered safe for most applications, such as in light bulbs and electronics. However, tungsten dust or fumes generated during welding or manufacturing processes can be harmful if inhaled. Proper safety measures should be taken to minimize exposure to tungsten dust and fumes.
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.
What are the substances in tungsten?
Tungsten is a pure element with the chemical symbol W. In its natural form, it exists as the metal tungsten.
What is ore of tungsten?
Tungsten is commonly found in minerals such as wolframite and scheelite. These minerals are the main ores from which tungsten is extracted.
What is Tungsten original name?
Tungsten's original name is Wolfram that is why the symbol for Tungsten is a W
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
Maximum load 1800W resistive - 600W tungsten?
The maximum load for resistive devices is 1800W, while for tungsten devices it is 600W. This means that devices with resistive load can safely draw up to 1800W of power, while devices with a tungsten load should not exceed 600W to prevent damage to the equipment and ensure safety.
