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  • Question

  • With increase in temperature, the electrical conductivity would


  • Options
  • A. increase in metals as well as in intrinsic semiconductor
  • B. increase in metals but decrease in intrinsic semiconductor
  • C. decrease in metals but increase in intrinsic semiconductor
  • D. decrease in metals as well as in intrinsic semiconductor

  • Correct Answer
  • decrease in metals but increase in intrinsic semiconductor 

    Explanation
    Increase in temperature causes resistivity of metals to increase and resistivity of intrinsic semiconductors to decrease.

    Conductivity is reciprocal of resistivity.

    More questions

    • 1. In pulse width modulation of chopper

    • Options
    • A. T is kept constant and Ton is varied
    • B. Ton is kept constant T is varied
    • C. both T and Ton are varied
    • D. either T or Ton is varied
      • Discuss
    • 2. The colour code on a carbon resistor is green-blue-yellow. The tolerance is

    • Options
    • A. ± 5%
    • B. ± 10%
    • C. ± 20%
    • D. ± 30%
      • Discuss
    • 3. Wave guides are pressurised above normal atmospheric pressure for

    • Options
    • A. increasing the power handling capacity
    • B. improving conductivity of walls
    • C. preventing higher modes from propagation
    • D. varying the wave impedance
      • Discuss
    • 4. A transmission line discontinuity is defined as any interruption in the uniformity of the line.

    • Options
    • A. True
    • B. False
      • Discuss
    • 5. Which of the following is not a valid variable name in C?

    • Options
    • A. 1 a
    • B. a 1 2
    • C. a b 123
    • D. a b c 123
      • Discuss
    • 6. If an amplifier with gain of - 1000 and feedback factor ? = - 0.1 had a gain change of 20% due to temperature, the change in gain of the feedback amplifier would be

    • Options
    • A. 10%
    • B. 5%
    • C. 0.2%
    • D. 0.01%
      • Discuss
    • 7. Permeability is analogous to

    • Options
    • A. resistivity
    • B. retentivity
    • C. conductivity
    • D. coercivity
      • Discuss
    • 8. In a Gunn diode oscillator drift velocity of electron is 107 cm/s and active region length is 10 x 10-4 cm. The natural frequency of oscillation is

    • Options
    • A. 1 MHz
    • B. 10 MHz
    • C. 1 GHz
    • D. 10 GHz
      • Discuss
    • 9. A cycloconverter is a group of controlled rectifiers.

    • Options
    • A. True
    • B. False
      • Discuss
    • 10. If the valence electron is separated from a copper atom, the remaining part of atom has a net charge of

    • Options
    • A. 1
    • B. - 1
    • C. 0
    • D. + 3
      • Discuss

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