0
Why must the gate to source voltage of an n channel Jfet always be zero or negative?
Wiki User
∙ 8y ago
to made reverse bias junction between gate to source
Wiki User
∙ 11y ago
Add your answer:
Earn +20 pts
Define pinch off voltage and the gate source cut off voltage?
If negative voltage is applied to the gate of a NMOS, it repels electrons from the channel region towards the bulk of the p-substrate and attaract holes from p-substrate towards the channel. The recombination between holes and electrons causes a deplation of majority carriers in the channel. Enough nagative gate voltage can cause the channel depleted of majority carriers and cuts off the current between the source and the drain. The least negative gate voltage causing this is called gate-source cut off voltage.
What are depletion and enhancement mosfet?
A depletion MOSFET is a MOSFET that is normally on. It outputs maximum current when the gate-source voltage is 0V. As the gate-source voltage increases, the drain-source channel becomes more resistive and the current decreases. An enhancement MOSFET has the opposite behavior. It is normally off. It outputs no current when the gate-source voltage is 0V. As the gate-source voltage increases, the drain-source channel becomes less resistive and the current increases.
If the resistance increases what will happen to voltage and current?
If you have a simple circuit. For eg: One voltage source and one resistor, then the voltage of the circuit will always remain the same, the current however will decrease following Ohms' Law V=I*R. If we have a current source instead of a voltage source, we are forcing the current to be a certain value so if we increase the resistor value the current will remain the same but the voltage will increase.
What is the voltage source and what is the conductor in a circuit?
The voltage source is the source of the electricity. The conductor is what the electricity flows through to reach its destination. Example: A battery is a voltage source and an electrical wire is the conductor.
2 What is Pinch-off voltage of JFET?
To find out the qualitative response to changes in Vgs and Vds, consider Vgs =0. In response to a small applied voltage Vds, a n-channel JFET acts as a simple semiconductor resistor and Id increases linearly with Vds. With increasing current, the ohmic voltage drop between the source and the channel region reverse biases the junction and the conducting portion of the channel begins to constrict. because of the ohmic drop along the length of the channel itself, the constriction is not uniform but is more pronounced at distances father from the source. Eventually, a Vds is reached at which the channel is "pinched off". At this voltage, Id begins to level off. and approach a constant value. It is not possible for the channel to close completely and reduce Id to zero. If that were the case, then the ohmic drop required to provide the back biasing would be lacking.Id is not equal to zero at Pinch off voltage.Thus, pinch off voltage can be defined as the gate reverse voltage that removes all the free charge from the channel.
Define pinch off voltage and the gate source cut off voltage?
If negative voltage is applied to the gate of a NMOS, it repels electrons from the channel region towards the bulk of the p-substrate and attaract holes from p-substrate towards the channel. The recombination between holes and electrons causes a deplation of majority carriers in the channel. Enough nagative gate voltage can cause the channel depleted of majority carriers and cuts off the current between the source and the drain. The least negative gate voltage causing this is called gate-source cut off voltage.
What is always true during the operation of an electrolytic cell?
the negative terminal of the voltage source is attached to cathrode.
What does the voltage used by each part of a circuit always adds up to?
A: the source voltage
Why do protons move away from high voltage?
Protons respond to any voltage, and moreso to high voltage. If a proton is moving away from high voltage, it must be because the high voltage source is positive. A positive will repel a positive. Certainly if the high voltage was negative, the proton would be moving toward the source. The basic laws of electrostatics apply.
What does the positive and negative symbols represent in energy source?
Relative charge. (And/or relative voltage.)
What is Cut-off voltage in fet?
fet is a voltage controlled device...cut off voltage in fet refers to that voltage of the gate - source junction at which the current flow through channel is zero
Fet in cut off voltage?
fet is a voltage controlled device...cut off voltage in fet refers to that voltage of the gate - source junction at which the current flow through channel is zero
Why do you always use voltage source in lab not current source?
Current is created by voltage (potential difference), not the other way round. It's the voltage - or 'push' - that is making your current move.
What are depletion and enhancement mosfet?
A depletion MOSFET is a MOSFET that is normally on. It outputs maximum current when the gate-source voltage is 0V. As the gate-source voltage increases, the drain-source channel becomes more resistive and the current decreases. An enhancement MOSFET has the opposite behavior. It is normally off. It outputs no current when the gate-source voltage is 0V. As the gate-source voltage increases, the drain-source channel becomes less resistive and the current increases.
Why peak voltage of the load is smaller than the voltage from the transformer output?
The voltage appearing across a load is always smaller than the no-load voltage of any voltage source -e.g. batteries, generators, or transformers. In simple terms this is because all these voltage sources have internal resistance or impedance which results in an internal voltage drop when the source delivers a load current. The resulting voltage, therefore, is always the difference between the no-load voltage and the internal voltage drop. A measure of the difference between a source's no-load and full-load voltage is termed its 'voltage regulation'.
What will happen when the terminal of the volmeter are inversed and used to read the voltage of the DC supply?
Depends on the voltmeter. Some meters will display a positive voltage no matter how the leads are attached to the source. Others may indicate a negative voltage if leads are reversed.Another AnswerAn analogue voltmeter will always read downscale (i.e. 'backwards') if connected the wrong way around.Digital voltmeters generally indicate the correct voltage, but display a negative sign to indicate that the polarity is the wrong way around.Don't forget, when we say 'negative voltage', we are referring to its direction. Voltage, which is simply another word for 'potential difference', and it cannot be positive or negative in the sense of 'charge'.
What is source of voltage?
Energy is the source of voltage
