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What is a beta emitter?
In physics, an alpha emitter is a radioactive substance which decays by emitting alpha particles.
How does using a transistor with a different beta affect the operation of the common emitter amplifier?
Gain, in the common emitter amplifier, is beta (hFe) or collector resistance divided by emitter resistance, whichever is less. Substituting a different beta (hFe) transistor will affect gain, if hFe is less, or increase stability and design margin, if hFe is greater.
When the forward saturation in Bipolar junction transistor occurs?
Forward saturation in a BJT occurs when the ratio of collecter-emitter current and base-emitter current reaches hFe or dc beta. A that point, the BJT is no longer operating in linear mode.
What is meant by dependent source?
A dependent source is a source that is dependent on, i.e. a function of, some other thing in the circuit. Often, a transistor is represented as a dependent current source, with collector-emitter current being dependent on base-emitter current times hFe, or beta-gain, limited by the collector-emitter resistor network.
Why is the positron emitter more than beta emitter in medium nuclei?
Electrons being negatively charged will be attracted by the protons within the nucleus and so they come after spending energy against the force of attraction. But positron being positively charged will be repelled by positively charged portons. Hence the energy difference between electron and positron emission in case of beta decay
What is a beta emitter?
In physics, an alpha emitter is a radioactive substance which decays by emitting alpha particles.
Why positron emitter is more than beta emitter in medium nuclie?
Because there is more energy available, and beta+ decay requires an energy contribution, as opposed to beta-.
Which radioisotope is a beta emitter?
90-Sr is the answer.
How does using a transistor with a different beta affect the operation of the common emitter amplifier?
Gain, in the common emitter amplifier, is beta (hFe) or collector resistance divided by emitter resistance, whichever is less. Substituting a different beta (hFe) transistor will affect gain, if hFe is less, or increase stability and design margin, if hFe is greater.
How you differentiate base bias and emitter bias?
On the emitter there is base current which is basically a function of Beta and only at that particular current. Unfortunately the beta factor is a non linear function and it is strictly related to collector current
Can positions of emitter and collector can be interchanged?
No, Beta plummets dramatically. Operation would be severely degraded.
What was technetium used for?
Technetium-99m is used as tracer in medicine and as beta-emitter standard source.
What is actinium -227?
Actinium-227 is a natural isotope; the half life is 24,77 years. It is a emitter of alpha and beta.
What is the typical base-to-collector amplification factor of CA3046 BJT?
The typical base-emitter gain (beta or hFE) of a CA3046 is 100, at an emitter current of 100ma. This translates to a base-collector gain (alpha) of 0.99.
How do you calculate the current gain of a transistor?
Bipolar transistor current gain is also called "Beta," or the h-parameter "hfe." beta = current_out / current_in The beta of a BJT is mostly determined by the thickness of the Base region, and by the excess doping in the Emitter relative to the Base. A thin Base and a heavily-doped Emitter leads to a high value for current gain. In a BJT, beta = Ic / Ib In a FET, beta is usually taken as infinity, since no current flows in or out of the gate. Beta is an impirical number. It means nothing unless the Ic is known or the load. It can have a beta from 1000 to 10 it all depends on the load.
Why output of common emitter amplifier is inverted?
In a common emitter amplifier, the base-emitter current causes a corresponding collector-emitter current, in the ratio of hFe (beta gain) or collector resistance over emitter resistance, which ever is less. Since this ratio is usually greater than one, the differential collector current is greater than the differential base current. This results in amplification of the base signal. As you increase the base-emitter current, the collector-emitter current also increases. This results in the collector being pulled towards the emitter, with the result that the differential collector voltage decreases. This results in inversion of the base signal.
What is the difference between a transistor used as a switch and an amplifier?
A transistor used as a switch is operated in saturated mode, where the ratio of base-emitter current over collector-emitter current is far more than hFe, or beta gain. The transistor is either fully on or fully off in this mode. A transistor used as an amplifier is operated in linear mode, where the ratio of base-emitter current over collector-emitter current is equal to or less than hFe, or beta gain. The transistor is partially on in this mode, and is operating as a current controlled current sink.
