Question

What is non linear resistance?

Answer 1

Non-linear resistance refers to a type of resistance in which the current through a material or component is not directly proportional to the voltage applied across it. In other words, when a voltage is applied to a non-linear resistor, the relationship between the voltage and the current doesn't follow Ohm's Law (which states that \(V = IR\), where \(V\) is the voltage, \(I\) is the current, and \(R\) is the resistance).

Key Characteristics of Non-linear Resistance:

1. Variable Resistance: The resistance of a non-linear resistor changes depending on the applied voltage or current. As voltage increases, the resistance may either increase or decrease, unlike in linear resistors where it stays constant.
   

1. Curve Behavior: The \(V\)-\(I\) (voltage vs current) graph of a non-linear resistor is not a straight line. Instead, it is a curve, showing how the resistance varies at different voltage levels.
   

Common Examples:

1. Diodes: A diode's resistance is non-linear because the current-voltage (I-V) characteristic follows an exponential curve.
   

1. Thermistors: These are resistors that change resistance with temperature. Some thermistors (like Negative Temperature Coefficient or NTC thermistors) show a non-linear relationship between temperature and resistance.
   

1. Transistors: In certain configurations, transistors can exhibit non-linear resistance.
   

Why Does It Matter?

1. Applications in Circuits: Non-linear resistors are used in various electronic components, such as diodes and transistors, which are essential for rectifying, switching, and amplifying signals.
   

1. Power Dissipation: Non-linear resistors can also lead to complex behaviors in circuits, especially when high voltages or currents are involved.
   

In summary, non-linear resistance is when the resistance of a component changes depending on the applied voltage or current, and this causes a curve rather than a straight line in the \(V\)-\(I\) relationship.