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Electrical

Resistors:
Resistor is an electrical component that provides electrical resistance to a circuit. Resistors are used to decrease the flow of current.

Principle of Resistors:
Ohms law:
Ohms law states that the voltage across the resistor is proportional to current, where the constant of proportionality is resistance.


Symbols of resistors are:
Here a= resistor, b= rheostat and c is potentiometer.

Types of resistors
1. Power Resistors
2. Variable Resistors


Effect of temperature in resistor:

1. Metal conductor
Temp and resistance increases with increase in temperature.
Rt=Ro(1+alpha0t)
positive temperature cofficient

2. Semi conductor
Temperature increases and resistance decreases with increase in temperature.
Rt=Ro(1-alpha0t)
negative temp coffecient

3. Isulator
Temperature increases and resistance decreases with increase in temperature.


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