Pn junction diode experiment readings and graph pdf

Pn junction diode experiment readings and graph pdf


  • PN Junction Diode Characteristics – Explained in Detail with Graphs
  • To obtain V-I characteristics of Zener Diode with Graph – Electronics Practical
  • To study and verify the functionality of a pn junction diode in forward bias b point contact diode in reverse bias components equipments required.

    A zener diode when forward biased behaves like an ordinary p n junction diode. Pn junction diode experiment observations. A zener diode when reverse biased can either undergo avalanche break down or zener break down. Avalanche break down if both p side and n side of the diode are lightly doped depletion region at the junction widens.

    Definition p type semiconductor is suitably joined to n type semiconductor to conduct surface is called pn junction. Plot a graph with reverse voltage along x axis and reverse current along y axis.

    Simulator procedure as performed through the online labs select the characteristics of diode from the drop down list. A pn junction diode is one of the simplest semiconductor devices around and which has the characteristic of passing current in only one direction only.

    Smartereveryday recommended for you. To draw the i v characteristic curve of a p n junction in forward bias and reverse bias physics lab manualncert solutions class 12 physics sample papers aim to draw the i v characteristic curve of a p n junction in forward bias and reverse bias.

    An isolated pn junction makes a semiconductor diode. The graph shows the reverse v i characteristics of the given p n junction diode. Bipolar npn transistors for example are made by sandwiching a p layer in between two n layers hence the name npn. Name quantity name quantity. Why snatch blocks are awesome how pulleys work smarter every day duration.

    Pn junction diode characteristics lab expriment 1. Experiment 6observation of the v i characteristic of a diode debangshu mukherjee bsc physics1st year chennai mathematical institute 1 aim of experiment we try to see the voltage current realtion in diodes by applying a voltage across it and measuring the corressponding current owing through it 2 apparatus required aa diode. It is called cut in voltage. In forward bias condition current is constant until certain voltage is reached.

    The behaviour of the pn junction with regards to the potential barriers width produces an asymmetrical conducting two terminal device better known as the pn junction diode.

    Forward reverse bias characteristics of pn junction diode. Other semiconductor components are made from more complicated arrangements. Pn junction diode characteristics 2. Apparatus a p n junction semi conductor diode a 3 volt battery a 50 volt.

    The current through an ideal pn junction is given by the diode equation. A pn junction diode is formed when a single crystal of semiconductor is doped with acceptors impurities pentavalent on one side and donor impurities trivalent on the other side.

    We talked a lot about barrier potential but did we ever mention its value? From the graph, we observe that the diode does not conduct at all in the initial stages. From 0 volts to 0. This means the diode has not started conducting current through it.

    From 0. From this data what you can infer? The barrier potential of silicon diode is 0. The diode starts conducting at 0. It conducts current linearly with increase in voltage applied across the 2 terminals provided the applied voltage crosses barrier potential. What happens inside the pn junction diode when we apply forward bias? We have seen the characteristics of pn junction diode through its graph. What really happens inside the diode during the forward bias?

    We know a diode has a depletion region with a fixed barrier potential. This depletion region has a predefined width, say W. This width will vary for a Silicon diode and a Germanium diode. The width highly depends on the type of semiconductor used to make pn junction, the level of doping etc. When we apply voltage to the terminals of diode, the width of depletion region slowly starts decreasing. The reason for this is, in forward bias we apply voltage in a direction opposite to that of barrier potential.

    We know the p-side of diode is connected to positive terminal and n-side of diode is connected to negative terminal of battery. So the electrons in n-side gets pushed towards the junction by force of repulsion and the holes in p-side gets pushed towards the junction. As the applied voltage increases from 0 volts to 0. This means depletion region vanishes at 0.

    This results in increased diffusion of electrons from n-side to p-side region and the increased diffusion of holes from p-side to n-side region. How current flow takes place in a pn junction diode? This is another interesting factor, to explain.

    As the voltage level increases, the electrons from n-side gets pushed towards the p-side junction. Similarly holes from p-side gets pushed towards the n-side junction. Now there arises a concentration gradient between the number of electrons at the p-side junction region and the number of electrons at the region towards the p-side terminal.

    A similar concentration gradient develops between the number of holes at the n-side junction region and the number of holes at region near the n-side terminal. This results in movement of charge carriers electrons and holes from region of higher concentration to region of lower concentration. This movement of charge carriers inside pn junction gives rise to current through the circuit.

    Reverse biasing a PN junction diode Why should we reverse bias a pn diode? The reason is, we want to learn its characteristics under different circumstances. By reverse biasing, we mean, applying an external voltage which is opposite in direction to forward bias. So here we connect positive terminal of battery to n-side of the diode and negative terminal of the battery to p-side of the diode.

    This completes the reverse bias circuit for pn junction diode. Now to study its characteristics change in current with applied voltage , we need to repeat all those steps again. Connect voltmeter, ammeter, vary the battery voltage, note the readings etc etc. Finally we will get a graph as shown.

    Analysing the revere bias characteristics Here the interesting thing to note is that, diode does not conduct with change in applied voltage.

    The current remains constant at a negligibly small value in the range of micro amps for a long range of change in applied voltage. When the voltage is raised above a particular point, say 80 volts, the current suddenly shoots increases suddenly. What happens inside the diode? We connected p-side of diode to negative terminal of battery and n-side of diode to positive terminal of battery. So one thing is clear, we are applying external voltage in the same direction of barrier potential.

    The electrons at n-side will get pulled from junction region to the terminal region of n-side and similarly the holes at p-side junction will get pulled towards the terminal region of p-side.

    As width of depletion region increases, it results in increasing the electric field strength. How reverse saturation current occurs and why it exists? The reverse saturation current is the negligibly small current in the range of micro amperes shown in graph, from 0 volts to break down voltage.

    It remains almost constant negligible increase do exist in the range of 0 volts to reverse breakdown voltage. How it occurs? We know, as electrons and holes are pulled away from junction, they dont get diffused each other across the junction.

    What remains is the drift due to electric field. This reverse saturation current is the result of drifting of charge carriers from the junction region to terminal region. This drift is caused by the electric field generated by depletion region. What happens at reverse breakdown?

    At breakdown voltage, the current through diode shoots rapidly. Even for a small change in applied voltage, there is a high increase in net current through the diode. For each pn junction diode, there will be a maximum net current that it can withstand. If the reverse current exceeds this maximum rating, the diode will get damaged. Conclusion about PN junction characteristics To conclude about pn junction characteristics, we need to get an answer to the first question we have raised — What is the use of pn junction?

    From the analysis of both forward bias and reverse bias, we can arrive at one fact — a pn junction diode conducts current only in one direction — i. During forward bias, the diode conducts current with increase in voltage. During reverse bias, the diode does not conduct with increase in voltage break down usually results in damage of diode. Where can we put this characteristics of diode into use?

    Hope you got the answer! Its in conversion of alternating current to direct current AC to DC. So the practical application of pn junction diode is rectification!

    A zener diode when reverse biased can either undergo avalanche break down or zener break down. Avalanche break down if both p side and n side of the diode are lightly doped depletion region at the junction widens. Definition p type semiconductor is suitably joined to n type semiconductor to conduct surface is called pn junction. Plot a graph with reverse voltage along x axis and reverse current along y axis.

    Simulator procedure as performed through the online labs select the characteristics of diode from the drop down list.

    A pn junction diode is one of the simplest semiconductor devices around and which has the characteristic of passing current in only one direction only. Smartereveryday recommended for you. To draw the i v characteristic curve of a p n junction in forward bias and reverse bias physics lab manualncert solutions class 12 physics sample papers aim to draw the i v characteristic curve of a p n junction in forward bias and reverse bias.

    An isolated pn junction makes a semiconductor diode. This is another interesting factor, to explain. As the voltage level increases, the electrons from n-side gets pushed towards the p-side junction. Similarly holes from p-side gets pushed towards the n-side junction.

    Now there arises a concentration gradient between the number of electrons at the p-side junction region and the number of electrons at the region towards the p-side terminal. A similar concentration gradient develops between the number of holes at the n-side junction region and the number of holes at region near the n-side terminal.

    This results in movement of charge carriers electrons and holes from region of higher concentration to region of lower concentration.

    This movement of charge carriers inside pn junction gives rise to current through the circuit.

    Reverse biasing a PN junction diode Why should we reverse bias a pn diode? The reason is, we want to learn its characteristics under different circumstances. By reverse biasing, we mean, applying an external voltage which is opposite in direction to forward bias. So here we connect positive terminal of battery to n-side of the diode and negative terminal of the battery to p-side of the diode.

    This completes the reverse bias circuit for pn junction diode. Now to study its characteristics change in current with applied voltagewe need to repeat all those steps again. Connect voltmeter, ammeter, vary the battery voltage, note the readings etc etc. Finally we will get a graph as shown. Analysing the revere bias characteristics Here the interesting thing to note is that, diode does not conduct with change in applied voltage. The current remains constant at a negligibly small value in the range of micro amps for a long range of change in applied voltage.

    When the voltage is raised above a particular point, say 80 volts, the current suddenly shoots increases suddenly.

    PN Junction Diode Characteristics – Explained in Detail with Graphs

    What happens inside the diode? We connected p-side of diode to negative terminal of battery and n-side of diode to positive terminal of battery. So one thing is clear, we are applying external voltage in the same direction of barrier potential.

    The electrons at n-side will get pulled from junction region to the terminal region of n-side and similarly the holes at p-side junction will get pulled towards the terminal region of p-side.

    To obtain V-I characteristics of Zener Diode with Graph – Electronics Practical

    Pn junction diode characteristics experiment complete with readings graph cbse pnjunction zener forwardbias reversebias follow us on facebook httpsw. You can notice the corresponding ammeter and voltmeter readings. This may lead to damage the diode. Diode i v characteristics the i v graph for a non ideal diode is. Readings just plot a graph with voltmeter readings on x axis and corresponding ammeter readings on y axis. Experiment guide components required for this lab. Pn junction diode experimentin.

    Tabulate different reverse currents obtained for different reverse voltages. Zener diode characteristics experiment readingsin hindi 2. Experiment 6observation of the v i characteristic of a diode debangshu mukherjee.


    thoughts on “Pn junction diode experiment readings and graph pdf

    1. In my opinion, it is an interesting question, I will take part in discussion. Together we can come to a right answer. I am assured.

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