Ideal resistors are independent of temperature. However, resistor that use high temperature wire do change resistance as a function of power and temperature. You can solve the problem graphically or with a computer and a model of the resistor that accounts for the temperature and resistance dependence on power.

There is no simple answer. Components are selected for a specific



temperature range, and when the range is broad the components



become increasingly exotic.



Metals tend to increase resistance as temperature increases.



Switches use a "tungsten rating" because an incandescent bulb



can draw 10 times it's rated power instantaneously.



Semiconductors tend to lose resistance with increasing resistance.



Carbon resistors increase in resistance below room temperature,



and increase again above it.



See below for details.

Objects do have variable resistance, especially when they undergo large changes in temperature. Generally its resistance does go up if its temperature goes up. Resistance is NOT proportional to temperature, however. For small currents and consequently not much change in temperature resistance does not change much so that Ohm's law is useful.

when current flow through the conductor it starts to heating but because its atmosphere is normal so heat is released to the atmosphere at the same rate by which conductor is heating, so overall effect is only the constant resistance which conductor have

So I know that when current flows through a resistor, the resistor heats up. I also know that resistance is proportional to the object's temperature.

So if a resistor is getting heated up by an electric current, will its overall resistance increase as a result? So objects have variable resistance? I'm confused.