What causes resistance in a wire?
The moving electrons can collide with the ions in the metal. This makes it more difficult for the current to flow, and causes resistance. The resistance of a long wire is greater than the resistance of a short wire because electrons collide with more ions as they pass through.
How does the resistance of a wire depends on its length?
Resistance of a wire is directly proportional to the length of the wire. The resistance of a conductor depends on the number of collisions which the electrons suffer with the fixed positive ions while moving from one end to the other end of the conductor. Therefore, a longer conductor offers more resistance.
Why is resistance directly proportional to length?
For a given material, resistance and length formula clearly speaks that the resistance is directly proportional to its length. When the length of the material is increased, its value of resistance also increases. When the length of the material decreases, its value of resistance will also decrease.
Does resistance decrease as temperature increases?
The more these atoms and molecules bounce around, the harder it is for the electrons to get by. Thus, resistance generally increases with temperature. In some materials (like silicon) the temperature coefficient of resistivity is negative, meaning the resistance goes down as temperature increases.
What will happen to the resistance if the temperature of a resistor is increased?
Increasing the temperature (typically) increases resistance. The temperature coefficient of resistance (TCR) of wire or a resistor relates the change in resistance to the change in temperature.
Does resistance increase with voltage?
Resistance doesn’t increase directly because of Voltage. Increasing the voltage for a circuit with a given resistance increases the current flow.
What happens when a resistor gets hot?
Burning of Resistor When a resistor has been overloaded with voltage exceeding its power rating, the resistor will become very hot to touch, darken considerably and possibly even melt or catch on fire. Although a resistor may appear damaged at this point, it can still be functioning.