Final answer:
The positive temperature coefficient resistor start device is a type of resistor, designed to increase its resistance as the temperature rises, which can protect circuits from overheating by reducing current flow.
Step-by-step explanation:
The positive temperature coefficient resistor start device is a type of resistor. A positive temperature coefficient means that the resistance increases as the temperature rises. This is in contrast to some materials which have a negative temperature coefficient, where resistance decreases with an increase in temperature.
Resistors like these are widely used in circuits to ensure stability or protect against current surges by compensating for temperature changes. The positive temperature coefficient resistor can help prevent a circuit from overheating by reducing the current as it warms up. The temperature coefficient of resistivity is an empirical quantity represented by the symbol α, which describes how the resistance or resistivity of a material changes with temperature.
Resistors are known to dissipate power in the form of heat when current passes through them, in accordance with Ohm's law, which states that V = IR, where V is voltage, I is current, and R is resistance. The power dissipated can be found using the equation P = I2R or P = V2/R.