0
Why dc supply is being used in studying the effect of temperature on the field winding resistance of a dc motor?
Wiki User
∙ 8y ago
Because tests on a dc motor are always done using dc.
Wiki User
∙ 8y ago
Add your answer:
Earn +20 pts
What is effect of temperature on conductor?
It depends on the material. In metals, the resistance increases with temperature.
What is the effect of the temperature on the resistance?
It varies. On some items resistance goes up, some it goes down when temperature goes up.
What factors effect the resistance of a conductor?
Factors affecting the resistance of a conductor include the material from which it is made, its length, its cross-sectional area, and its temperature.
What is a air temp sensor?
IAT air intake sensor is a thermistor ( a resistor that varies the value of it's resistance in accordance with temperature changes ) the change in the resistance values will directly effect the voltage signal from the sensor to the PCM/ECM. As the sensor temperature increases, the resistance values will decrease. As the sensor temperature decreases the resistance values will increase.
Does temperature increase affect resistance?
Yes. The exact effect - whether it increases or decreases - depends on the material.
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.
If voltage is high will the resistance be high?
The electric resistance is related to the diameter and extension of the wire submitted to a determined voltage which will determine the electric current flowing into the wire.AnswerVoltage has no effect on resistance. Resistance is determined by the length, cross-sectional area, and resistivity of a material (resistivity is affected by temperature, so temperature indirectly affect resistance).
What is the effect of temperature on resistance of different metals?
with increase temperature in metal, thermal energy causes atoms in metal to vibrate, in this excited state atoms interact with and scatter electrons, thus decreasing the mean free path, and hence the mobility of electrons to decreases and resistivity increase(Resistivity = 1 / Conductivity )so conductivity of metal decrease as increasing in temperature
How Magnetism effect resistance?
Magnetism does not affect the resistance of a conductor. The factors affecting resistance are the conductor's length, cross-sectional area, and resistivity. As resistivity is affected by temperature, temperature indirectly affects resistance. However, the changing magnetic field surrounding a conductor carrying an AC current causes the current to flow closer to the surface rather than being distributed throughout the cross-section of the conductor. The greater the frequency, the greater this effect. This has the equivalent effect of reducing the cross-sectional area of the conductor, causing its resistance to rise. This is misleadingly called the 'AC resistance' of the conductor!
Does air temperature affect air resistance?
There are two factors that influence air resistance with temperature. Air density decreases with temperature so that the force needed to push the air out of the way is decreased, thereby decreasing resistance. Conversely, air viscosity increases with temperature (unlike oil for example where viscosity decreases with temperature) so that the drag increases. Under normal conditions, the density change of air has the greatest effect and air resistance decreases at higher temperatures.
What is the effect of temperature on specific resistance of wire?
increase of temp cause increase of specfic resistance...... bcz atoms exictes and cause hindrance in motio of free electons so by increasing temp specfic resistance increasaes
What is the formula to calculate AC resistance if the DC resistance is known?
AC resistance is the term used to describe the elevated value of resistance due to the reduction in a conductor's effective cross-sectional area due to the the skin effect caused by an alternating current. The skin effect describes how AC current tends to flow towards the surface of a conductor, rather than being distributed across the entire cross-sectional area as is the case for a DC current.For 50/60 Hz supplies the skin effect is not great and, so, there will not be a great difference between the DC resistance and AC resistance of a winding. Accordingly, it will be very difficult to calculate the winding's AC resistance, as its value is likely to be masked by experimental error and the accuracy of the instruments.In theory, by using a wattmeter and an ammeter, the resistance of a load -in this case a winding- the readings can be inserted into the equation: R = P/I2. Using a DC supply will reveal the (DC) resistance value, and using an AC supply will reveal the AC resistance value. As explained, a combination of experimental error and instrument accuracy is very likely to mask any actual difference between the two resulting values.So, at mains' frequencies, the difference between AC resistance and actual (DC) resistance would be very difficult to determine with any degree of accuracy.
