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  • Question

  • A thyristor has a maximum allowable junction temperature of 120°C and the ambient temperature is 40°C. If thermal resistance is 1.6° C/W, the maximum allowable internal power dissipation is


  • Options
  • A. 20 W
  • B. 50 W
  • C. 92 W
  • D. 128 W

  • Correct Answer
  • 50 W 

    Explanation
    A thyristor has a maximum allowable junction temperature of 120°C and the ambient temperature is 40°.

    More questions

    • 1. In a single phase full wave ac regulator using two thyristors only, the gate circuits of the two thyristors

    • Options
    • A. must be isolated
    • B. may or may not be isolated
    • C. should be preferably, isolated
    • D. should not be isolated
      • Discuss
    • 2. In a ripple counter,

    • Options
    • A. whenever a flip flop sets to 1, the next higher FF toggles
    • B. whenever a flip flop sets to 0, the next higher FF remains unchanged
    • C. whenever a flip flop sets to 1, the next higher FF faces race condition
    • D. whenever a flip flop sets to 0, the next higher FF faces race condition
      • Discuss
    • 3. Maximum efficiency of class B power amplifier is 50%.

    • Options
    • A. True
    • B. False
      • Discuss
    • 4. Which of the following commutation methods is the overall circuit under damped?

    • Options
    • A. Class A
    • B. Class B
    • C. Class C
    • D. Both class A and Class B
      • Discuss
    • 5. The primary constants of a transmission line are

    • Options
    • A. R and L
    • B. R, L and C
    • C. R and C
    • D. R, L, G and C
      • Discuss
    • 6. For the strip line in the given figure the capacitance per unit length =

    • Options
    • A.
    • B.
    • C.
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      • Discuss
    • 7. In which mode of circular waveguide does the attenuation continuously decrease as frequency is increased?

    • Options
    • A. TE01
    • B. TE11
    • C. TE05
    • D. TE21
      • Discuss
    • 8. The beam of a radar should be

    • Options
    • A. very narrow
    • B. very wide
    • C. neither too narrow nor very wide
    • D. either (b) or (c)
      • Discuss
    • 9. If temperature is increased, the temperature coefficient of a metal

    • Options
    • A. increases
    • B. decreases
    • C. may increase or decrease
    • D. remains constant
      • Discuss
    • 10. In an homogeneous dielectric subjected to an electric field E, the dipole moment per unit volume is ?0(?r - 1) E.

    • Options
    • A. True
    • B. False
      • Discuss

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