What is the effect of temperature on ohms law?

Answer 1

The effect of temperature on Ohm's Law is that the resistance of most materials changes with temperature, which in turn affects the current and voltage relationship described by Ohm's Law. Specifically:

• Resistance Increase: For most materials, such as metals, resistance increases with temperature. This can lead to higher resistance in a circuit as it heats up, which can reduce current if the voltage remains constant.

• Resistance Decrease: Some materials, like semiconductors, show decreased resistance with increasing temperature. This can lead to increased current if the voltage remains constant.

Ohm's Law itself (V=IR) remains valid, but the value of resistance (R) can change with temperature, altering the relationship between voltage (V) and current (I).

Answer 2

Answer

One of the conditions for Ohm's Law to apply is that the temperature of a conductor MUST remain constant. And, unfortunately, this is difficult to achieve because as the applied voltage increases, the resulting current causes the temperature of the conductor to rise -thus negating Ohm's Law!!

For Ohm's Law to apply, the ratio of voltage to current must remain constant for variations in voltage. If it doesn't, then the conductor/device is NOT obeying Ohm's Law. Period! So if, for example, you increase the voltage across a lamp, you will find that the ratio varies as the voltage increases, and this is because the resistance is increasing due to an increase in temperature. So, in this example, the temperature is the reason why lamps don't obey Ohm's Law.