A lamp has two resistances: a 'hot' resistance (its operating resistance) and its 'cold' resistance (its resistance when switched off), and the hot resistance is significantly higher than its cold resistance.You can calculate its 'hot' resistance from its rated power and its rated voltage (assuming that it is being supplied at its rated voltage), by manipulating the following equation, to make Rthe subject: P= V2/RYou will, though, have to measure its cold resistance.
It means exactly what it sounds like. The resistance of an incandescent bulb's filament depends on its temperature. A filament has a positive temperature coefficient, which means that its resistance increases as its temperature increases. A typical 40 watt bulb (120 volts) has a cold resistance of about 28 ohms, but its hot, operating resistance is about 360 ohms. If the cold resistance were constant, the bulb would dissipate 379 watts. In fact, cold turn on is the most stressful time for a bulb.
By Ohm's law, resistance is voltage divided by current, so the resistance of a light bulb can be measured by observing the voltage across it simultaneously with observing the current through it. Interestingly, the hot resistance is significantly different that the cold resistance, so measuring resistance with an ohmmeter will not give a meaningful resistance. This is because the resistance of a light bulb has a positive temperature coefficient. Take a typical 60 W 120V light bulb, for instance... Its cold resistance is about 16 Ohms. Calculate current and power at 120 V and you get 7.5 A and 900 W. The truth is that at 60 W, the bulb pulls 0.5 A and has a resistance of 240 Ohms.
the therminster will get hotter when the resistance is lowed
I think you mean, 'insulation' resistance! It's the resistance of insulation, normally expressed in megohms.
A conductor has low electrical resistance when hot and higher electrical resistance when cold. This is due to the increased thermal agitation of electrons in the conductor when it is hot, causing higher resistance compared to when it is cold.
If you are asking if a hot wire has a greater resistance than a cold wire then the answer I would say is yes. Cold wires have always had less resistance than hot wires
Cold resistance refers to a material's ability to withstand low temperatures without damage or degradation. Hot resistance, on the other hand, is a material's ability to withstand high temperatures without damage or structural changes. Both properties are important considerations in choosing materials for various applications.
A lamp has two resistances: a 'hot' resistance (its operating resistance) and its 'cold' resistance (its resistance when switched off), and the hot resistance is significantly higher than its cold resistance.You can calculate its 'hot' resistance from its rated power and its rated voltage (assuming that it is being supplied at its rated voltage), by manipulating the following equation, to make Rthe subject: P= V2/RYou will, though, have to measure its cold resistance.
u mean hot AND cold? Katy perry
Cold and heat fatigue is one of the main forms of failure of hot work dies, and the molds for supporting pictures should have high resistance to cold and heat fatigue.
Cold air is more dense, thus is gives more resistance. Notice how you land when you're flying. In the winter, it's usually a smooth gradual landing. In summer, you hit the runway with much more force.
FIRE for HOT andICE for COLD
Yes, in hot air the air is a lot thinner so there is less resistance compared to cold air which is a lot denser so more resistance.
When ur hot and ur working then it is hot working, if ur cold and ur working then it is cold working
can you please clarify what you mean, do you mean that the front heater blows cold but the rear blows hot or do you mean that when the heating is on cold it blows hot? many thanks paul
When we call something hot we mean that its temperature is high, and when we call something cold we mean that its temperature is low.