Nothing Special   »   [go: up one dir, main page]
Scribd Logo
Upload

Welcome to Scribd!

  • 28 views

    Mock Answer Electronics

    Uploaded by

    ERMIAS Amanuel
    This document provides a summary of key concepts in applied electronics and semiconductor devices: - When the temperature of a doped semiconductor increases, its conductivity also increases due to more charge carriers exciting to the conduction band. - Various semiconductor devices like diodes, transistors and MOSFETs are discussed in terms of their operating characteristics, configurations and applications. Transistors commonly operate in saturation and cutoff regions in digital circuits. - Multistage amplifiers provide higher total gain but their bandwidth decreases due to loading effects between stages. Darlington amplifiers offer high current gain but have tradeoffs like higher input/output impedances. - Key parameters like voltage, current and power gains are defined along with their

    Copyright:

    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd

    Mock Answer Electronics

    Uploaded by

    ERMIAS Amanuel
    28 views12 pages
    This document provides a summary of key concepts in applied electronics and semiconductor devices: - When the temperature of a doped semiconductor increases, its conductivity also increases due to more charge carriers exciting to the conduction band. - Various semiconductor devices like diodes, transistors and MOSFETs are discussed in terms of their operating characteristics, configurations and applications. Transistors commonly operate in saturation and cutoff regions in digital circuits. - Multistage amplifiers provide higher total gain but their bandwidth decreases due to loading effects between stages. Darlington amplifiers offer high current gain but have tradeoffs like higher input/output impedances. - Key parameters like voltage, current and power gains are defined along with their

    Original Description:

    mock

    Copyright

    © © All Rights Reserved

    Available Formats

    PDF, TXT or read online from Scribd

    Did you find this document useful?

    Is this content inappropriate?

    This document provides a summary of key concepts in applied electronics and semiconductor devices: - When the temperature of a doped semiconductor increases, its conductivity also increases due to more charge carriers exciting to the conduction band. - Various semiconductor devices like diodes, transistors and MOSFETs are discussed in terms of their operating characteristics, configurations and applications. Transistors commonly operate in saturation and cutoff regions in digital circuits. - Multistage amplifiers provide higher total gain but their bandwidth decreases due to loading effects between stages. Darlington amplifiers offer high current gain but have tradeoffs like higher input/output impedances. - Key parameters like voltage, current and power gains are defined along with their

    Copyright:

    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd
    Download as pdf or txt
    28 views12 pages

    Mock Answer Electronics

    Uploaded by

    ERMIAS Amanuel
    This document provides a summary of key concepts in applied electronics and semiconductor devices: - When the temperature of a doped semiconductor increases, its conductivity also increases due to more charge carriers exciting to the conduction band. - Various semiconductor devices like diodes, transistors and MOSFETs are discussed in terms of their operating characteristics, configurations and applications. Transistors commonly operate in saturation and cutoff regions in digital circuits. - Multistage amplifiers provide higher total gain but their bandwidth decreases due to loading effects between stages. Darlington amplifiers offer high current gain but have tradeoffs like higher input/output impedances. - Key parameters like voltage, current and power gains are defined along with their

    Copyright:

    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd
    Download as pdf or txt
    You are on page 1of 12

    Applied Electronics I

    1
    1. When the temperature of a doped semiconductor increased, its
    Conductivity__
    A) Increases or Decreases depending on whether it is P –or N-type
    B) Decreases
    C) Does not change
    D) Increases
    • Answer: D) ✓ When the temperature of a doped semiconductor is increased,
    the number of charge carriers increases since the thermal energy supplied to
    electrons in the valence band forces them to excite to the conduction band.
    As a result, the number of electrons in conduction band increases and holes in
    valence band increases so, conductivity increases.
    2. In N type semiconductor, the position of Fermi level:
    A) In Conduction Band
    B) Near Conduction Band
    C) Near Valance Band
    D) In Valance Band
    3. When the crystal diode current is large, the bias is_______
    A) Forward
    B) Small
    C) Large
    D) Reverse
    Answer: A) ✓
    4. You have an application for a diode to be used in a tuning circuit. A type of
    diode to use might be;
    A) Schottky diode
    B) Gunn diode
    C) An LED diode
    D) Varactor diode
    Answer: D) ✓
    Varactor diode is a simple variable capacitor that allows oscillator and other
    circuits to be easily tuned by applying a voltage
    5. The forward characteristic of a diode has a slope of approximately 20mA/V
    at a desired point. The approximate incremental resistance of the diode is:
    A) 50Ω
    B) 20Ω
    C) 35Ω
    D) 10Ω
    • Answer: A) ✓ The reciprocal of the slope of I-V graph gives the resistance
    of diode as: 1/slope= 1/(20x10-3 A/V)= 50Ω
    6. The process of emitting photons from a semi-conductive material is
    called____
    A) Gallium Phosphide
    B) Electroluminescence
    C) Gallium Arsenide
    D) Photoluminescence
    • Answer: B) ✓ Electroluminescence is a process by which photons are
    generated when the excess electron–hole pairs are created by an electric
    current caused by an externally applied bias
    7. In a PNP transistor, the current carriers are______
    A) Holes
    B) Acceptor Ions
    C) Free Electrons
    D) Donor Ions
    Answer: A) ✓ In a pnp transistor, current carriers are holes b/c holes are
    existed in excess amount than free electrons.
    8. What configuration is widely preferred in cascading amplifier?
    A) Common Source
    B) Common Emitter
    C) Common Collector
    D) Common Base
    • Answer: B) ✓Common Emitter configuration offers both current and
    voltage gain resulting in higher power gain than the other configurations
    9. The lowest output Impedance is obtained in case of BJT amplifiers for:
    A) CE with RE Configuration
    B) CC Configuration
    C) CE Configuration
    D) CB Configuration
    • Answer: B) ✓ The CC amplifier configuration has the lowest output
    Impedance compared to the other BJT Configurations
    10. When transistors are used in digital circuits, they usually operate in the___
    A) Saturation and Cutoff Region
    B) Breakdown Region
    C) Linear Region
    D) Active Region
    Answer: A) ✓ Since digital circuit is an electrical circuit that uses binary logic
    to process binary data either (0 or 1). Zero refers OFF while 1 represent ON.
    A Transistor is used in digital circuits as ON switch in Saturation mode and
    OFF switch in Cutoff Mode
    11. Often a common collector will be the last stage before the load.
    The main function of this stage is:
    A) To buffer the voltage amplifiers from the low resistance load and
    provide impedance matching for maximum power transfer
    B) To provide phase inversion of the input signal
    C) Provide a high frequency path to improve the frequency response
    D) To provide voltage gain at the load
    Answer: A) ✓
    12. An N channel D-MOSFET with a positive VGS is operating in_______
    A) The Depletion mode
    B) Cutoff mode
    C) The Enhancement mode
    D) Saturation mode
    Answer: C) ✓ The operating region with positive VGS in N channel D-
    MOSFET is called Enhancement operational region

    13. Enhancement mode MOSFETs are more commonly used as


    A) Buffers
    B) Resistors
    C) Switches
    D) Capacitors
    Answer: C) ✓
    14. The total gain of a multistage amplifier is less than the product of the gains
    of individual stages due to________
    A) Loading effect of the next stage
    B) Power loss
    C) The use of many transistors
    D) The use of many capacitors
    Answer: A) ✓
    15. What happens to the bandwidth if the total gain increased in cascade
    amplifiers?
    A) Increases
    B) Infinite
    C) Remains the same
    D) Decreases
    Answer: D) ✓ In cascade amplifiers voltage gain increases which in turn
    reduces the bandwidth to maintain a constant gain-bandwidth product.
    16. If Av, Ai and Ap represents the voltage gain, current gain and power gain
    ratio of an amplifier which of the following is correct expression for the
    corresponding values in decibel?
    A) Current gain: 10log(Av) dB
    B) Power gain:20log(Ap) dB
    C) Power gain: 10log(Ap) dB
    D) Voltage gain: 10log(Av) dB
    Answer: C) ✓
    Since
    Current gain: 20log(Ai) dB
    Voltage gain: 20log(Av) dB
    Power gain: 10log(Ap) dB
    17. The main characteristics of a Darlington Amplifier are:
    A) High input Impedance, Low output Impedance and High Current gain
    B) High input Impedance, High output Impedance and High Current gain
    C) Low input Impedance, Low output Impedance and High Current gain
    D) Low input Impedance, Low output Impedance and Low Current gain
    Answer: A) ✓
    Darlington Amplifier has
    • High input Impedance,
    • Low output Impedance
    • High Current gain
    Good Luck

    You might also like