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In a Silcon diode no current flows in the forward direction (anode to positive voltage) until approximately 0.6 - 0.7Volts is reached. Above this voltage the current rises in line with Ohms Law. In the reverse direction only micro Amps flow (leakage current)
In a Germanium diode the threshold is about 0.2 volts and reverse leakage is higher.
What else can I help you with?
What is the voltage across diode carrying a constant current?
increases
Is the vi characterreistics curve of a pn diode is linear or exponential?
A diode has a fixed voltage drop (c), and if the voltage is less than that, no (or very little) current flows. Once the voltage increases above the voltage drop, the current increases exponentially as the voltage increases. A function that models this is: I = exp(b*(V-c)) where V is the voltage, I is the current, c is the voltage drop and b is a parameter that determines how fast the current increases; the value of b varies from one diode to another
What happens to zener current after the breakdown voltage is reached?
After breakdown voltage is reached in a zener diode the current increases drastically.
How does the ac resistance of a diode change as the voltage increases?
When the voltage increases the temperature in the diode also increases. When the temperature in the diode increases, the resistance decreases.
What is the lifetime of barrier voltage in a diode?
The barrier voltage of a diode is 0.7v for silicon and 0.3 for germanium. after this voltage is reached the current starts increasing rapidly... till this voltage is reached the current increases in very small steps...
What is the voltage across diode carrying a constant current?
increases
Is the vi characterreistics curve of a pn diode is linear or exponential?
A diode has a fixed voltage drop (c), and if the voltage is less than that, no (or very little) current flows. Once the voltage increases above the voltage drop, the current increases exponentially as the voltage increases. A function that models this is: I = exp(b*(V-c)) where V is the voltage, I is the current, c is the voltage drop and b is a parameter that determines how fast the current increases; the value of b varies from one diode to another
What happens to zener current after the breakdown voltage is reached?
After breakdown voltage is reached in a zener diode the current increases drastically.
How does the ac resistance of a diode change as the voltage increases?
When the voltage increases the temperature in the diode also increases. When the temperature in the diode increases, the resistance decreases.
What is the lifetime of barrier voltage in a diode?
The barrier voltage of a diode is 0.7v for silicon and 0.3 for germanium. after this voltage is reached the current starts increasing rapidly... till this voltage is reached the current increases in very small steps...
When temperature increases voltage across diode with constant current?
The voltage across a semiconductor diode (and across the base/emitter junction of a transistor) decreases as temperature increases: the actual figure is -2mV/°C.
What are the voltage and current characteristics of a series circuit?
The voltage and current characteristics of a zener diode in the forward bias condition (anode more positive than cathode) are similar to an ordinary diode. Below the cutoff voltage, the current is near zero, excepting for leakage current. Starting at the turnon voltage, the diode starts to conduct. As voltage increases, current increases. At this point, increases in current result in very small increases in voltage. Above the breakdown current, the diode tends to self-destruct. The cutoff voltage for a silicon diode typically ranges from 0.6V to 0.7V, and the beginning of the flat region ranges from 0.7V to 1.4V, depending on the current rating of the diode. The cutoff characteristic is also highly dependent on temperature. It is important to understand that, while the current to voltage curve is relatively flat between the cutoff and breakdown points, it is not completely flat. This is normal diode behavior. In the reverse bias condition (anode more negative than cathode), the zener diode behaves very much like its forward bias condition, except that the cutoff voltage and flat region range are higher and, sometimes, flatter. This is what a zener is used for - it makes a good voltage regulator.
How may type of resistors in diode?
None. A diode does not have a resistor in it. Diodes and resistors are different devices used for different purposes. For example, increasing current flow through a resistor increases the voltage drop across the resistor. Increasing current flow through a diode (within the diode's capabilities, just the same as a resistor) will actually decrease the voltage drop across the diode (once the diode "turns on" this voltage variance will be fairly small, though).
When current through a zener diode increases by a factor of 2 by what factor does the voltage across the zener diode increase?
If the zener diode is in zener breakdown the voltage across the zener diode remains constant regardless of current (for the ideal zener diode). Real zener diodes have parasitic resistance that causes the voltage across the zener diode to increase slightly with increased current, but due to temperature dependant variations in this parasitic resistance as well as temperature dependant variations in the zener breakdown voltage, this change in voltage in real zener diodes cannot be described by a simple linear factor.
What is the condition that prevent the current to pass across diode?
if the voltage across the diode is less than the cut-in voltage of that particular diode .
What is the cutting voltage of a silicon diode?
It is not 'Cutting voltage' but it is Cut-in voltage'. It is the voltage at which the diode turns ON. For silicon it is 0.7v. After reaching 0.7V diode current starts increasing rapidly for little increase in voltage.
Is a zener diode a current limiter?
No. A zener diode is a voltage limiter. Circuit design might create a current limiting response, but the basic control is voltage, not current.
