0
The principle of heating a filament to obtain a movement of electrons is called?
Wiki User
∙ 12y ago
Thermionic emission
Wiki User
∙ 12y ago
Add your answer:
Earn +20 pts
What scientific principle did Jacques Charles discover?
Charles' Law describes how gases expand when they are heated. Jacques Charles conducted experiments by filling balloons with various types of gases, then heating them and observing how they expanded.
Can you give me 2 fact about the incandescant light bulb?
-It's a very old technology quickly being replaced by newer more efficient technologies. -The light produced in the bulb is created by electricity heating up a filament inside the bulb creating light. This wouldn't be possible without the bulb however, since oxygen would quickly end this reaction of the filament through oxidation.
Does a large current in a circuit make a bulb bright or dim?
The glow of the bulb is due to heating of the filament to the incandescent level. Joule's heating effect gives the formula H = I2 R t. Hence more the current then more the heat and so more brightness. Thus large current makes the bulb brighter no doubt. At the same time if current exceeds the nominal level then filament would get melted and get fused.
How does gas water heater work?
The gas water heater works through a principle of physics which is known as convection. The gas heater is similar to a water heater only that it has one heating unit.?æ
Caused by the uneven heating of the atmosphere?
Wind is caused by the uneven heating of the atmosphere. When an area has warmer air than surrounding areas, the air rises which creates a region of low pressure. The areas around it have higher pressure, and therefore air moves from there to the low pressure area. The movement of this air is called wind.
What is the difference between filament current and tube current?
The current supplied to the filament for heating is defined as the Filament current. whereas When the filament is heated to a high temperature, the electrons are emitted. The flow of electrons form Cathode to anode is the tube Current.
What is filament current?
The current supplied to the filament of an electron tube for heating.
What is an electrical current and what causes it?
Electrical current is nothing but movement of electrons in case of metals. It causes heating and produces magnetic field.
How does a light bulb demonstrate the heating effect?
by the radiation in the filament it throw out heat . this way the bulb demonstrates the heating effect. :D
Do metals gain electrons during heating?
Heating has no influence.
The emission of electrons in high-vacuum tubes is caused by?
The heating by the filament causes the electrons to "boil off". Edison noted this phenomena and it was later picked up by Fleming who used a "grid" which could control the flow of the electrons by introducting a repelling field between the Cathode (heated element that emitted the electrons) and the anode that attracted the free electrons, thus the "Fleming Valve" was invented (the vacuum tube.
Why do lightbulbs burn out?
They burn out from 1) the rapid heating and cooling of the Tungsten filament, and 2) from the tungsten atoms being released from the metal filament by way of the extremely high temperatures. Eventually the tungsten metal fails and the filament breaks.
What makes the light bulb special?
Well, the filament of an incandescent light bulb is what emits light. This is achieved by taking a thread of tungsten (the "filament") and suspending it in either a vacuum or an inert gas. This is done to prevent the tungsten from combustion when it heats up. The filament then has an electric charge passed through it heating the filament and causing it to emit light photons. The reason this happens is that when electrons (electricity) flow across the tungsten atom they collide with the electron of the tungsten atom causing the electrons to move to a higher energy level temporarily. The electron then emits a light photon expending energy and moving it back to its original energy level where the process starts all over again.
Why should the filament of bulbs be thermally isolated?
Energy, in the form of electricity, causes the filament to heat up and give off light. Any energy which the filament loses by heating the bulb does not create light, and so is wasted. Thermal isolation minimizes the heat loss of the filament, and therefore reduces wasted energy.
Why electrical resistivity of metals change with increasing laser shots?
it is similar to that of heating a metal heating a metal leads to increase in resistance thus both laser shot or heating are form of heat transfer that leads the atoms to higher energy states causing random movement of electrons vigorously which increases resistance
How is light created in light bulbs?
By heating a wire (the filament) by passing electricity through it until it is white hot.
Why does the resistance in a series circuit which includes a light bulb increase when the bulb lights up?
When the current increases as a voltage is applied to the bulb it causes the bulb's special wire filament to get so hot that it glows very brightly. The heating causes changes in the normal electron lattice of the filament, creating more barriers to the flow of the electrons and therefore the resistance of the wire increases as it gets hotter.
