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For most conductors as their temperature increases their resistance?
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∙ 12y ago
The resistance of pure metallic conductors increases with temperature, because the resistivity of these conductors increase with temperature.
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∙ 12y ago
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What do you expect of ohmic resistance as you increase or reduce temperature?
It depends. In general, pure metal conductors increase in resistance as their temperature increases; some alloys (e.g. constantan) are manufactured to maintain an approximately-constant resistance for changes in temperature. Materials such as carbon (and most insulators) exhibit a fall in resistance as their temperatures increase.
When the resistance in a circuit increases what happens to the current flow?
"Ohms Law" defines resistance (R) as the the ratio of voltage (V) to current (I).R = V/IIf you move those variables around, you can get the formula:I = V/RSo you can see that when resistance increases, current flow will decrease.CommentResistance is most definitely not defined as 'the ratio of voltage to current', although that ratio may tell you what it happens to be.Resistance isn't a variable in the Ohm's Law equation. It is a constant because it is unaffected by either current or resistance.
What part of a light bulb has the most resistance?
the actual filament itself in a light bulb has the most resistance,this is why it glows and produces light,the rest of the bulb is sufficiently engineered to carry the voltage and current applied to it without producing too much heat.
The devices thgat do not follow ohms law?
All devices follow Ohm's law. Ohm's law states that voltage is equal to current times resistance. This is always true. DC, AC, RF, whatever. Resistance, capacitance, or inductance, whatever. Its a matter of proper perspective, and its a matter of taking everything into account.Some devices do not have a linear response to voltage or current.Take the light bulb, for instance. If you measures its resistance you can calculate what you think its current and power would be at a certain voltage, and you would be wrong, unless you also considered temperature. This is because light bulbs have a very dramatic resistance to temperature coefficient. As an example, a 40W applicance bulb might have a cold resistance of 27 ohms. That translates to 4.4A or 533W, with a 120V source. The truth is that the 40W bulb has a hot resistance of 360 ohms, giving an on current of 0.333A and an on power of 40W, with a 120V source.For another example, look at the diode. Initially, it appears to have high resistance. When the voltage across it reachs the forward bias voltage (or the reverse bias voltage for a zener diode) it starts to conduct and draw current. As you increase the current, you note that the voltage is relatively constant. That is certainly not a resistor - the diode's resistance is increasing as current increases so as to make the voltage be somewhat constant. You can still calculate voltage, current, resistance, and power, but only at each point of observation.For the last example, though not really an example of non-linear resistance, consider the capacitor. In a DC circuit, the capacitor initially has zero ohms resistance, but it quickly rises to infinity ohms depending on current and capacitance. In an AC circuit, this a much more interesting and useful case - the capacitor stabilizes at a certain capacitive reactance, and the operation of the curcuit complies with Ohm's law, but lo and behold - you find that the current is no longer in phase with the voltage. While this complicates calculations, nothing changes the fact that voltage is current times resistance. That is an immutable given - your task is to learn how to measure it correctly.In each of these cases, and in any other case, Ohm's law applies, but it applies in a certain way, under a certain set of circumstances. The bulb has 360 ohms of resistance at 120V, giving 0.333A and 40W. That is very clear. What you must maintain equally clear is that resistance is not always a constant - and you must consider that inconstancy every time you change the conditions of the circuit.AnswerOhm's 'Law' is somewhat of a misnomer, because it is not really a universal law because it only applies to a small range of conductors. Ohm's Law only applies when the ratio of voltage to current is constant for variations in voltage. Devices that follow Ohm's Law are called linear or ohmic; those that don't are called non-linear or non-ohmic. Most metal conductors are linear, but some are not. For example, tungsten does not obey Ohm's Law because its ratio of voltage to current changes as the voltage applied across it changes -in other words, tungsten is non-linear. Electronic devices, such as diodes, electrolytes, and gases are all non-linear and do not obey Ohm's Law.Having said that, the ratio of voltage to current will always tell you what the resistance of a device happens to be for that particular ratio and, so, the equation R = V/I applies to all devices whether they are linear or non-linear. However, this equation is not derived from Ohm's Law, but from the definition of resistance.
What is the purpose of a digital temperature controller?
There are many purposes for a digital temperature controller in everyday life. Most people however use digital temperature controllers to control the temperature in their refrigerators.
Temperature coefficient of resistance?
most metals resistance increases with temperature
Why internal resistance of the battery decreases as temperature increases?
R is inversely related to temperature T so as temperature increases resistance decreases. Specifically, R increases if the T coefficient is pos.(P.T.C) And decreases if T coefficient is neg. (N.T.C) Most conductors have P.T.C and most insulators have (N.T.C) . xept. like carbon. 1 of few conductors that has a N.T.C. But all can be found on a tablet. R.T.C / R mil-foot ,R, millimeter-meter and R.T.C @ 68*F
What do you expect of ohmic resistance as you increase or reduce temperature?
It depends. In general, pure metal conductors increase in resistance as their temperature increases; some alloys (e.g. constantan) are manufactured to maintain an approximately-constant resistance for changes in temperature. Materials such as carbon (and most insulators) exhibit a fall in resistance as their temperatures increase.
Do The resistance of a material generally increases as its temperature increases?
The answer to this depends on the material from which the resistance is made. For most materials resistance increases with increasing temperature. This is referred to as having a "positive temperature coefficient". Some materials have a negative temperature coefficient; these do have uses in electronics.
What happens to the resistance of a material with a positive temperature coefficient when it is heated?
Positive Temperature coefficient indicates that the resistance of material INCREASES with rise in the temperature. Resistance Temperature COefficient(RTC) is defined as increase in resistance per unit original resistance per unit rise in temperature. Temperature Coefficient of Resistance=R2-R1/(R1*(T2-T1)) Where: R2:Resistance at temperature T2 R1:Resistance at temperature T1 SO from formula it is clear that if resistance increases with temperature(T2-T1>0 and R2>R1) then Difference R2-R1 will be positive hence RTC will have positive value. But if with increase in temperature(T2-T1>0) resistance decreases(R2<R1) then difference R2-r1 will be negative hence RTC will be negative.
What is principle of thermistor?
The thermistors are resistors whose resistance changes with the temperature. While for most of the metals the resistance increases with temperature, the thermistors respond negatively to the temperature and their resistance decreases with the increase in temperature. Since the resistance of thermistors is dependent on the temperature, they can be connected in the electrical circuit to measure the temperature of the body.
The solubility of most solids as the temperature increases?
For most solids, as the temperature increases the solubility increases.
What is meant by cold resistance of filament lamp?
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.
What shows how conductors insulators superconductors and semiconductors rank in order of least resistance to most resistance?
The sequence is as follows:
HOW DOES conductance vary with temperature?
yes temperature affects the conductivity of conductor and semi conductors but in case of insulators temp. has no effect. While we talk about conductors as temp. increases conductivity decreases ,the question is why, look if we take an example of copper the conductivity is so high at normal temperature because the molecules in the copper are so close but when we increase temperature the inter molecule distance increases and result is increasing resistance of the copper, and as we know that resistance is inversely proportional to the conductivity. So in the case of conductor, temperature affects the conductivity. Hey may be you are familiarize with the new aspect called superconductivity, the same effect is here while the temperature of a conductor is so low approximately -273degree the conductor becomes superconductor because Resistance become so low (can say approx. 0 but not exact 0). You should know that most metals increase their electrical resistivity by about 0.005 per degree. Good luck Rjames007
What is the difference between superconductors and normal conductors?
Normal conductors have resistance which restricts the flow of electricity and wastes some of the energy as heat. The resistance increases with the length of the conductor. Superconductors have close to zero or zero resistance and a few other properties, but the resistance is the most important one because it means electricity can flow more efficiently through it. The drawback is that all the superconductors we know of today have to be cooled down to EXTREMELY low temperatures to achieve superconductivity.
Why do the densities of most substances derease with temperature?
resistance of only electrolytes and semiconductors decrease wid temp.This is so coz in these substance due to increase in temp, the no. of ions and electrolytes in conduction band increases .Thats why resistance decreases.
