V-l characteristics of Ohmic

Introduction:

V-l characteristics of Ohmic carry an important weightage in the IIT-JEE exams. Hence, it is important to have the best handy study material that will help the students clear their concepts on this topic. To make your preparations more productive, you can opt for Unacademy’s live classes and batch courses that are a great source to help you score more in the IIT-JEE exams.

V-l characteristics, Linear V-I Characteristics, Non-linear VI Characteristics, and V-I Characteristics of SCR are important concepts that the educators of the Unacademy have clearly explained. You also get to learn in detail about the relations of voltage and current variables via a V-I graph.

What is meant by a diode?

A diode is usually known as a semiconductor device that permits the current to flow in one direction. Diodes are devices that have two electrodes and are made from one semiconductor. The major types of semiconductors are p-type and n-type.

Define V-I Characteristics

V-I characteristics refer to voltage-current characteristics for any electrical device. The V-I graph plays an important role in delivering crucial information about the electric device’s resistance. It also gives a clear understanding of the device’s operational function in the electric circuit.

On a V-I graph, it is usually easier to keep the variable voltage on the x-axis and the variable current on the y-axis. Due to this, the voltage becomes an independent variable. When a V-I graph is drawn, the variable current is calculated when voltage is applied across an electric device.

What are the different types of V-I characteristics?

V-I Characteristics of SCR

SCR is the short form of a silicon-controlled rectifier. The V-I or voltage-current characteristics of SCR is a semiconductor switching device with three different terminals. This three-terminal device is utilized as the controlled switch for three different purposes. They are regulation, rectification, and inversion of the power flow.

Linear V-I Characteristics

The Linear V-I curve is the one that has a constant resistance and slope. Ohmic resistors represent a linear V-I characteristic. Here, the V-I curve is shown as a straight line that passes through the origin. The slope of this straight line helps calculate the resistance. And, it has been seen the higher the level of the slope, the more is the resistance.

Non-linear V-I Characteristics

A non-linear V-I characteristic is derived from situations where the V-I graph will not be linear, and resistance is not the same throughout. And, all of this significantly depends on either the current or the voltage that is applied. Some notable examples of non-linear V-I characteristics are transistors, diodes, SCRs, and more. Here are some important points about non-linear graphs;

The value between the V and I variables is not constant.

Here, the voltage applied is not proportional to the current.

The relationship or graph value between V and I depend on the variable voltage.

V-I Characteristics of a PN Junction Diode

Let’s consider that we have N-type material that is supposed to be fused with P-type material. N-type material includes more free electrons, and P-type holds more holes. When this fusion happens in order to make a semiconductor diode, then that becomes a PN junction diode. The PN junction diode has three biasing conditions, for example

•   Forward bias
•   Zero bias
•   Reverse bias

V-I Characteristics of an LED

LED refers to a light-emitting diode that has multiple applications and can be utilized in various semiconductor diode types that possess similar electrical characteristics to a PN junction diode.

What are the different applications of a PN Junction Diode?

•   p-n junction diode can be very well used a solar cell
•   When any diode acts in a forward-biased direction, it has great use in LED lighting applications
•   It can be utilized as an ideal voltage-controlled oscillator in the reactors and like a rectifier in different electric circuits

What happens if a diode is forward biased?

During forward biasing situations, the n-region is connected to the negative terminal that compels the electrons in the p-region. Likewise, the p-region is linked to the positive terminal, which makes the holes move in the n-region from the p-region. Because of this crucial movement between the holes and the electrons, there occurs a formation of neutral atoms.

When there is a decrease in the barrier potential, then there is a subsequent reduction in the width area of the formed depletion region. With a higher voltage supply, there is an increased conversion number of atoms into neutral atoms. This leads to the lesser availability of charged ions in the depletion region, and hence its width gets decreased. The fruitful conversion of the atoms into neutral atoms is a continuous process until the depletion region collapses. Due to this, a significant number of holes and electrons cross the junction, and the flow of current is in the direction of the anode to the cathode.

What happens if a diode is in a reverse-biased state?

When a diode is in a reverse-biased state, or we can say the cathode gets connected to the positive terminal (cathode), and anode gets connected to the negative terminal (anode), the cathode draws free electrons through the n-region, and the anode brings holes from the p-region. This leads to the broadening of the depletion region that counters the current flow. We know that the diode has infinite resistance when there is no current flowing, and it is a condition of a reverse-biased state. And, if there is a small leakage current, then that flows through the junction.

Conclusion

We hope this study material on V-l characteristics of Ohmic, Linear V-I Characteristics, Non-linear V-I Characteristics, and V-I Characteristics of SCR will help you answer questions related to this during your IIT-JEE exam.

The V-I graph is an important factor that helps determine the relationship between current and voltage in different conditions. For a better and clear understanding, Unacademy helps with live classes and mock tests on many more Physics topics that hold a vital role in the IIT exams. Engineering aspirants can anytime opt for Unacademy to boost their preparation strategies in order to get the best results.