Home/Analog Electronics Questions/Page 2
  1. Asked: December 18, 2022In:

    advantages of FETs over BJTs

    Best Answer
    Jemshah Enlightened

    Higher input impedance: FETs have a very high input impedance, which means that they do not draw much current from the input signal source. This makes them well-suited for use in high-impedance circuits and for amplifying low-level signals. In contrast, BJTs have a lower input impedance and are moreRead more

    1. Higher input impedance: FETs have a very high input impedance, which means that they do not draw much current from the input signal source. This makes them well-suited for use in high-impedance circuits and for amplifying low-level signals. In contrast, BJTs have a lower input impedance and are more sensitive to loading effects.
    2. Lower power dissipation: FETs typically have a lower power dissipation than BJTs, which means that they are less prone to overheating and can operate at higher temperatures. This makes them well-suited for use in high-power applications where heat dissipation is a concern.
    3. Greater frequency response: FETs typically have a faster response time and a higher frequency response than BJTs, which makes them well-suited for use in high-frequency circuits.
    4. Greater temperature stability: FETs are generally more stable over a wide range of temperatures than BJTs, which makes them well-suited for use in extreme temperature environments.
    5. Higher voltage handling: FETs are capable of handling higher voltage levels than BJTs, which makes them well-suited for use in high-voltage circuits.
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  2. Asked: December 18, 2022In:

    explain thermionic emission as applied to metals

    Best Answer
    Jemshah Enlightened

    Thermionic emission is the process by which electrons are emitted from a metal surface due to the application of heat. It is a phenomenon that occurs when a metal is heated to a high temperature, causing the electrons in the metal to gain enough energy to overcome the attraction of the positively chRead more

    Thermionic emission is the process by which electrons are emitted from a metal surface due to the application of heat. It is a phenomenon that occurs when a metal is heated to a high temperature, causing the electrons in the metal to gain enough energy to overcome the attraction of the positively charged atomic nuclei and escape from the surface of the metal.

    In thermionic emission, the metal surface acts as an electron emitter, and the emitted electrons are attracted to a negatively charged collector electrode. The process of thermionic emission is commonly used in vacuum tube devices, such as cathode ray tubes and vacuum tube amplifiers, as a means of generating an electron beam.

    Thermionic emission is related to the phenomenon of thermal conduction, in which heat is transferred through a material by the movement of free electrons. The rate of thermionic emission is dependent on the temperature of the metal, the work function of the metal, and the applied electric field. It is also affected by the surface roughness and cleanliness of the metal, as these factors can influence the ability of the electrons to escape from the surface.

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  4. Asked: December 18, 2022In:

    define i. atomic number ii. ionization potential with respect to atomic theory

    Jemshah Enlightened

    I. Atomic number: The atomic number of an element is the number of protons in the nucleus of an atom of that element. It is a characteristic property of an element and determines the element's place in the periodic table. The atomic number also determines the element's chemical behavior and the numbRead more

    I. Atomic number: The atomic number of an element is the number of protons in the nucleus of an atom of that element. It is a characteristic property of an element and determines the element’s place in the periodic table. The atomic number also determines the element’s chemical behavior and the number of electrons that an atom of that element has in its outermost energy level.

    II. Ionization potential: The ionization potential of an atom is the minimum amount of energy required to remove an electron from the atom. It is a measure of the atom’s electron affinity, or the energy required to add an electron to the atom. The ionization potential of an atom is determined by the strength of the attraction between the nucleus and the electrons in the atom. It is a fundamental property of an atom that is determined by the atomic number and is related to the arrangement of the electrons in the atom’s energy levels.

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