How does temperature affect a resistor?

Question

does a resistor become less affective (lower magnitude of ohms) as a result of the heat from a circuit?

Answer 1

A RESISTOR HAS A NEGATIVE TEMPERATURE COEFFICIENT, MEANING AS THE TERMPERATURE RISES THE RESISTANCE IN OHMS DOES TOO.

Answer 2

r = kt^4



Resistance is proportional to temperature (in Kelvin) to the 4th power.

Answer 3

When many materials (wires?) heat up, the increased vibration of their atoms (molecules) causes them to get in the way of free-flowing electrons which increases resistance to electroon flow.

Answer 4

How this property may be exploited for good purposes:



A thermistor is a temperature-dependent resistor. There are two kinds, classified according to the sign of their temperature coefficients:



A Positive Temperature Coefficient (PTC) resistor is a resistor with a positive temperature coefficient. When the temperature rises the resistance of the PTC increases. PTCs are often found in televisions in series with the demagnetizing coil where they are used to provide a short-duration current burst through the coil when the TV is turned on. One specialized version of a PTC is the polyswitch which acts as a self-repairing fuse.



A Negative Temperature Coefficient (NTC) resistor is also a temperature-dependent resistor, but with a negative temperature coefficient. When the temperature rises the resistance of the NTC drops. NTCs are often used in simple temperature detectors and measuring instruments.

Answer 5

The higher temperature applied to a resistor will increase the ohms of the resistor. Try this experiment: Take a small roll of copper wire and measure its resistance at nominal room temperature. Place this into a flask of warm water and apply heat to the flask. Connect an ohm meter and watch the resistance rise as the heat temperature goes up. Why? Since current flow is Q/t, the number of electrons passing a point in a given amount of time, the increase in temperature creates more activity in the structural atoms of the materiel. The electrons are slowing down because they are colliding with more atoms in the Warmer medium.

Answer 6

Increasing the temperature of the material makes the atoms more spaced out between each other. Therefore, the electrons have to jump more space to get to the next atom. This increases the material's resistance.

Important note: this property is not universal. There are exceptions.

Answer 7

Actually it becomes more resistive. I did an experiment once with a light bulb and discovered that when I first closed the switch the current would jump way up until the filament was at it's full glow, but then it quickly when down as the resistance increased due to heat and reached its equilibrium. So the wattage on the light bulb is the power that is running through it once it's reached it's equilibrium. With Cryogenics (super cooling) you can make materials less and resistive and some material has almost no resistance with cryogenics. Hope this answer helped.

Answer 8

For most materials, as the temperature increases, so does the resistance.



Materials that don't behave this way are deemed to have a "negative temperature coefficient".



It's left as an exercise for the student to identify these materials.

Answer 9

Higher temperature increases resistance (HIGHER OHMS). Therefore, a circuit will haeva greater resistance when it becomes hotter.