to determine the comparison of resistance value of both forward and reverse diode . The more the resistance the lower the current , the lower the resistance the higher the current . When reverse bias , the resistance is high and it acts in open circuit and the reverse current is very small that can be neglected . When forward bias , the resistance is low and it acts as short circuit and the forward current is increasing as the voltage supply is higher .
static resistance: This is measured when diode id forward biased and input is a D.C signal. The ratio of voltage applied to the current flowing through diode gives static resistance Dynamic resistance : this is measured when input is A.C signal. since A.C signal varies continuously the resistance offered also changes continuously. the ratio of change in voltage to change in current gives dynamic resistance.
Diodes do not obey Ohm's Law, at least when viewed as an individual component. When doing circuit analysis, however, you can make the case that, for a specific situation, they do. In fact, using this technique, everything "obeys" Ohm's law. In the simple case of a resistor, operated within its limits, Ohm's Law works just fine. Voltage is current times resistance. As voltage goes up, current goes up proportionately. You can predict the voltage or current knowing the other along with resistance. A diode, on the other hand, is non linear. As you apply voltage across it in the forward direction, it initially has high resistance. All of a sudden it has low resistance as it begins to conduct. As you increase the current, the resistance decreases, so the voltage drop is relatively (though not exactly) constant. At a certain point, around when you exceed the maximum forward current, the diode fails. In the reverse direction, an ordinary diode seems to have high resistance, until you reach about max reverse voltage, at which point the diode fails. In the case of a zener diode, reverse behavior is similar to forward behavior, except at a different voltage. Even though the diode does not obey Ohm's law, you can still use Ohm's Law to analyze the circuit. You just have to remember that the dynamic resistance of the diode changes as a function of the applied voltage. The value of Ohm's Law becomes evident when you consider that, at each static condition of the circuit, you do know the voltage and current through the diode and, as a result, you can use Ohm's law to calculate its dynamic resistance. This will allow you to extend the analysis by back substitution and simplification until you know more and more about the circuit.
The correct term is 'current', not 'amperage'. The answer is that nothing will happen to the resistance. Having said that, changing the resistance will cause current to change for a fixed value of voltage.Resistance is determined by the length, cross-sectional area, and resistivity of a material. Resistivity is affected by temperature, so resistance is also therefore indirectly affected by temperature. Only by changing one of these variables will the resistance change.Since the ratio of voltage to current will tell us what the resistance of a circuit happens to be (it's not affected by that ratio) for a particular ratio, the ratio will increase (as per your question) if the resistance increases. But it's not the ratio that's affecting resistance, its the resistance affecting the ratio!
Power factor is:the ratio of true power to apparent powerthe ratio of resistance to impedancethe ratio of the voltage across a circuit's resistive component to the supply voltagethe cosine of the phase angleetc.
Yes, the transistor acts like a diode. That is, essentially, what it does. What it also does, and what give it its added value and ability to amplify, is that the base current causes the collector-emitter "diode" junction to vary in its turn-on characteristic. With this ability, you can control a large current with a small current, and a small delta-current in the base causes a larger delta-current in the collector, the ratio being hFe, hence the term "gain".
ratio of ac voltage applied across the diode to the ac current flowing through it
static resistance: This is measured when diode id forward biased and input is a D.C signal. The ratio of voltage applied to the current flowing through diode gives static resistance Dynamic resistance : this is measured when input is A.C signal. since A.C signal varies continuously the resistance offered also changes continuously. the ratio of change in voltage to change in current gives dynamic resistance.
Forward Resistance:def: It is resistance offered by diode to the forward bias is known as forward resistance.This resistance is not the same for the flow of DC as for the changing current. Accordingly this resistance is of two types :1. DC FORWARD RESISTANCE.2. AC FORWARD RESISTANCE.1. DC forward resistance: It is the opposition by diode to the DC. It is measured by the ratio of DC voltages across the diode to the resulting DC current through it.2. AC forward resistance: It is the opposition offered by the diode to the changing current. It is measured by the ratio of change in voltage across diodes to the resulting change in current through diode. The AC forward resistance is more significant as the diodes are generally used with alternating voltage.Reverse Resistance:def: The resistance offered by the diode to the reverse bias is known as Reverse Resistance. It can be DC reverse resistance or AC reverse resistance depending upon whether the reverse bias is direct or changing voltage. Idealy the reverse resistance of a diode is infinte however in practice the reverse resistance is not infinite because for any value of reverse bias, there does exist a small leakage current. It may be emphasized their that reverse resistance is very large compared to the forward resistance.These Definitions are from PRINCIPLES OF ELECTRONICS by V.K MEHTA and ROHIT MEHTA
3.2
the cut in vol for silicon diode is 0.7 where as germaium is around 0.3 because of their construction( the ratio of majority n minority carreirs)
the cut in vol for silicon diode is 0.7 where as germaium is around 0.3 because of their construction( the ratio of majority n minority carreirs)
Diodes do not obey Ohm's Law, at least when viewed as an individual component. When doing circuit analysis, however, you can make the case that, for a specific situation, they do. In fact, using this technique, everything "obeys" Ohm's law. In the simple case of a resistor, operated within its limits, Ohm's Law works just fine. Voltage is current times resistance. As voltage goes up, current goes up proportionately. You can predict the voltage or current knowing the other along with resistance. A diode, on the other hand, is non linear. As you apply voltage across it in the forward direction, it initially has high resistance. All of a sudden it has low resistance as it begins to conduct. As you increase the current, the resistance decreases, so the voltage drop is relatively (though not exactly) constant. At a certain point, around when you exceed the maximum forward current, the diode fails. In the reverse direction, an ordinary diode seems to have high resistance, until you reach about max reverse voltage, at which point the diode fails. In the case of a zener diode, reverse behavior is similar to forward behavior, except at a different voltage. Even though the diode does not obey Ohm's law, you can still use Ohm's Law to analyze the circuit. You just have to remember that the dynamic resistance of the diode changes as a function of the applied voltage. The value of Ohm's Law becomes evident when you consider that, at each static condition of the circuit, you do know the voltage and current through the diode and, as a result, you can use Ohm's law to calculate its dynamic resistance. This will allow you to extend the analysis by back substitution and simplification until you know more and more about the circuit.
resistance force
what is ratio analysis
The correct term is 'current', not 'amperage'. The answer is that nothing will happen to the resistance. Having said that, changing the resistance will cause current to change for a fixed value of voltage.Resistance is determined by the length, cross-sectional area, and resistivity of a material. Resistivity is affected by temperature, so resistance is also therefore indirectly affected by temperature. Only by changing one of these variables will the resistance change.Since the ratio of voltage to current will tell us what the resistance of a circuit happens to be (it's not affected by that ratio) for a particular ratio, the ratio will increase (as per your question) if the resistance increases. But it's not the ratio that's affecting resistance, its the resistance affecting the ratio!
The correct term is 'current', not 'amperage'. The answer is that nothing will happen to the resistance. Having said that, changing the resistance will cause current to change for a fixed value of voltage.Resistance is determined by the length, cross-sectional area, and resistivity of a material. Resistivity is affected by temperature, so resistance is also therefore indirectly affected by temperature. Only by changing one of these variables will the resistance change.Since the ratio of voltage to current will tell us what the resistance of a circuit happens to be (it's not affected by that ratio) for a particular ratio, the ratio will increase (as per your question) if the resistance increases. But it's not the ratio that's affecting resistance, its the resistance affecting the ratio!
The ratio of resistance force to effort force is a mechanical advantage.