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Why does the resistance of a thermistor decrease as the temperature rises?
Some materials have negative temperature coefficients of resistance, and some have positive temperature coefficients. Carbon is an example of a substance with a negative thermal coefficient of resistance, so it's resistance will decrease as it gets hotter.
What is the resistance of a carbon rod at 25.8C if its resistance is 0.0160?
The resistance of a carbon rod can be affected by temperature changes, as carbon has a negative temperature coefficient. However, if the resistance is given as 0.0160 ohms at a specific temperature (in this case, presumably at room temperature), it is typically assumed to be measured at that temperature unless otherwise specified. Therefore, the resistance of the carbon rod at 25.8°C would remain approximately 0.0160 ohms if no additional temperature correction factor is applied.
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
Why the slope of voltage-resistance characteristic increases in the case of tungsten lamp and decresing in case of carbon lamp?
If the filament really was made from a material that has a negative temperature coefficient (as temperature increases, resistance decreases) then the decreasing resistance would cause more and more current to be taken as the lamp heated up and the temperature would get higher and higher in a runaway manner until either the power supply's breaker would trip or (more likely) the light bulb's filament would simply burn open. In fact the filament has to be made from a material that has a positive temperature coefficient. (As temperature increases, resistance increases.) Then, as the bulb's temperature rises, its filament's increasing resistance causes less current to be taken than when it was cold. Quite quickly a stable "steady-state" temperature and "running" resistance is reached so that the bulb simply continues to give out a steady amount of light according to the current it is taking from the electricity supply.
Does carbon have a nearly zero temperature coefficient of resistance?
Yes, carbon has a negative temperature coefficient. -0.5*10^3/C
Is there any change in resistance of carbon composition resistor due to change in temperature?
yes, calculate it from temperature coefficient of resistance.
Why does the resistance of a thermistor decrease as the temperature rises?
Some materials have negative temperature coefficients of resistance, and some have positive temperature coefficients. Carbon is an example of a substance with a negative thermal coefficient of resistance, so it's resistance will decrease as it gets hotter.
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.
What is the resistance of a carbon rod at 25.8C if its resistance is 0.0160?
The resistance of a carbon rod can be affected by temperature changes, as carbon has a negative temperature coefficient. However, if the resistance is given as 0.0160 ohms at a specific temperature (in this case, presumably at room temperature), it is typically assumed to be measured at that temperature unless otherwise specified. Therefore, the resistance of the carbon rod at 25.8°C would remain approximately 0.0160 ohms if no additional temperature correction factor is applied.
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
Why the slope of voltage-resistance characteristic increases in the case of tungsten lamp and decresing in case of carbon lamp?
If the filament really was made from a material that has a negative temperature coefficient (as temperature increases, resistance decreases) then the decreasing resistance would cause more and more current to be taken as the lamp heated up and the temperature would get higher and higher in a runaway manner until either the power supply's breaker would trip or (more likely) the light bulb's filament would simply burn open. In fact the filament has to be made from a material that has a positive temperature coefficient. (As temperature increases, resistance increases.) Then, as the bulb's temperature rises, its filament's increasing resistance causes less current to be taken than when it was cold. Quite quickly a stable "steady-state" temperature and "running" resistance is reached so that the bulb simply continues to give out a steady amount of light according to the current it is taking from the electricity supply.
What is the effect on the resistance of a carbon composition resistor as the current flow through it increases?
As current flowing through carbin composition resistor increses then resistance will decrese as the function of resistance is to oppose the flow of current.....AnswerA resistor is termed a 'linear' or 'ohmic' device, which means its resistance stays constant over a wide range of current variation -in other words, it obeys Ohm's Law up to the maximum current is designed to handle. If this were not the case, then the resistor would not be suitable for many applications. The maximum current it is designed to carry, before its resistance changes beyond its tolerance, is determined by its physical size, as the larger its surface area, the more efficiently it can dissipate heat.
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 the function of a carbon pile resistor in an electrical circuit?
A carbon pile resistor is used in electrical circuits to control the amount of current flowing through the circuit by adjusting its resistance. This helps regulate the voltage and prevent damage to the components in the circuit.
Does carbon have a nearly zero temperature coefficient of resistance?
Yes, carbon has a negative temperature coefficient. -0.5*10^3/C
As a carbon chain length increases viscostiy..?
Viscosity also increases with carbon chain length, at least of linear hydrocarbons.
Why carbon is used in brushes instead of semiconductor material in motor?
There are a number of reasons, including: 1. Carbon is self-lubricating. 2. Carbon has a negative temperature coefficient of resistance, which means that its resistance falls as its temperature increases -which is opposite that of metals such as copper. 3. Carbon is softer than copper, so will not damage the commutator. 4. Carbon will acquire the shape of the commutator segments and, so, will ensure maximum contact with them.
