Tungsten is a good conductor. Resistivity of tungsten is only about twice that of aluminum, and tungsten has lower resistance than iron, steel, platinum, lead. Note that the filament lead-in wires are typically iron, which has nearly twice the resistivity of tungsten.
The main difference between filament LEDs and regular LEDs is in the placement and number of individual LEDs in each bulb. While regular LEDs might use one large LED or a group of LEDs packed tightly into a small space, filament LEDs spread the diodes along several different lines or “filaments”.
Efficacy, efficiency
| Type | Overall luminous efficiency | Overall luminous efficacy (lm/W) |
|---|
| 60 W tungsten incandescent | 2.1% | 14.5 |
| 100 W tungsten incandescent | 2.6% | 17.5 |
| Glass halogen | 2.3% | 16 |
| Quartz halogen | 3.5% | 24 |
Tungsten is a metal, it is a good conductor of electricity. Also it is very hard and has very high melting point. Because of its high thermal stability and good conductivity properties it has many uses in electronic devices.
Tungsten light bulbs are named for the metal tungsten, a gray material that has an extremely high melting point. Because of its high melting point and its strength, it makes for a good filament in light bulbs. A filament is a metal wire that glows when electricity is channeled into it.
This wire is called a filament. The filament is the part of the light bulbthat produces light. Filaments in incandescent light bulbs are made of tungsten.
Explain that the “efficiency” of a light bulb is a measure of how much light energy comes out of the bulb compared to the amount of electricity (electrical energy) that was put in. A 100% efficient light bulb would convert all the electricity to light and not produce any heat at all.
When the current passes through the filament, it gets heated to incandescence and give light while the connecting wires are not heated because. A . The connecting wires are good conductor of heat while the filament is bad conductor.
Copper and aluminium offer a low resistance to the flow of current and hence they are good conductors of electricity. Copper being more ductile, it is used in making thin wires, and aluminium is used for making thicker wires. Thus, they are suitable for making wires used in electrical circuit.
Resistivity and Temperature Coefficient at 20 C
| Material | Resistivity ρ (ohm m) |
|---|
| Copper, annealed | 1.72 | x10-8 |
| Aluminum | 2.65 | x10-8 |
| Tungsten | 5.6 | x10-8 |
| Iron | 9.71 | x10-8 |
Electricity flows through a thin tungsten wire in the light bulb called the filament. A filament has a lot of resistance to electricity. As a result of this resistance, the filament heats up and starts glowing, converting electrical energy to light energy.
The stamen of a flower — the part that produces pollen — consists of a slender stalk, called a filament and an anther. The filament supports the anther, which is where pollen develops. The word filament is from the Latin word filum, which means "thread." Filament, in fact, can be a synonym for thread.
The coil shape allows a given fiber of tungsten to become hotter than it would if it were straight. The coils come in three types, single, double and triple and are each more efficient in that order.
No, copper wire cannot be used to make the filament of an electric bulb as copper wire has very low resistance. Therefore, the bulb will not glow if current is passed. It would also melt - the filament has to be white-hot to be any use!
Answer: It has low melting point. If it is used in electric heated it may melt and the heater get destroyed due to very high melting point the tungsten wire cannot used in elctric heater and another reason is that due to heating effect of current.
what will happen if we use a thick tungsten wire in a electric bulb? The bulb will not function properly. This is because the resistance of a thick wire is less than that of a thin wire. The filament should be having a high resistance in order to glow, which will definitely get reduced if we use a thicker wire.
why is copper wire not used in the filament of a bulb or as a heating element of heater? Resistivity of tungsten is higher than copper. If we use a thick tungsten wire in the electric bulb , then the resistance will get reduced and to achieve the requisite heat, more energy will be spent.
Tungsten is used because it do not flow in the bulb and make it to glow. (d) when electric current flows through the metal filament of the bulb it gets heated to a very high temperature.
(a) The melting point and of Tungsten is an alloy which has very high melting point and very high resistivity so does not burn easily at a high temperature. (e) Copper and aluminum are good conductors of electricity also they have low resistivity. So they are usually used for electricity transmission.
A: Copper has too low resistivity comparing to tungsten (1.68*10 ohm*m for copper vs 5.6*10 ohm*m for tungsten) so it would require much longer or thinner filament for same effective resistance, but first of all it has much lower melting point (1084 *C vs 3400*C) so it would not be able to shine this bright in the bulb
