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  • Question
  • An SCR has a turn on time of 4 ?s. The gate pulse should have a duration of about


  • Options
  • A. 2 ?s
  • B. 5 ?s
  • C. 20 ?s
  • D. 50 ?s

  • Correct Answer
  • 5 ?s 

    Explanation
    Duration of gate pulse should be slightly more than turn time of SCR.

    More questions

    • 1. An RC coupled amplifier has an open loop gain of 200 and a lower cutoff frequency of 50 Hz. If negative feedback with ? = 0.1 is used, the lower cut off frequency will be

    • Options
    • A. about 50 Hz
    • B. about 5 Hz
    • C. about 2.38 Hz
    • D. about 70.5 Hz
    • Discuss
    • 2. In a FM waveform, the side bands are spaced at intervals equal to

    • Options
    • A. four times the modulating frequency
    • B. twice the modulating frequency
    • C. half the modulating frequency
    • D. modulating frequency
    • Discuss
    • 3. In a loss line RL < Z0, then

    • Options
    • A. Reflection coefficient is zero
    • B. Reflection coefficient is ?
    • C. Reflection coefficient is negative
    • D. Reflection coefficient is positive
    • Discuss
    • 4. A communication channel with additive white Gaussian noise, has a bandwidth of 4 kHz and an SNR of 15. Its channel capacity is

    • Options
    • A. 1.6 kbps
    • B. 16 kbps
    • C. 32 kbps
    • D. 256 kbps
    • Discuss
    • 5. In a 7 segment display, LEDs b and c lit up. The decimal number displayed is

    • Options
    • A. 9
    • B. 7
    • C. 3
    • D. 1
    • Discuss
    • 6. The symbol in figure is for

    • Options
    • A. UJT
    • B. PUT
    • C. Shockley diode
    • D. TRIAC
    • Discuss
    • 7. The load impedance ZL of a CE amplifier has R and L in series. The phase difference between output and input will be

    • Options
    • A. 180°
    • B. 0
    • C. more than 90° but less than 180°
    • D. more than 180° but less than 270°
    • Discuss
    • 8. A pole zero pattern of a certain filter is shown in figure. This filter must be

    • Options
    • A. LPF
    • B. BFP
    • C. HPF
    • D. APF
    • Discuss
    • 9. To evaluate X = (A + B + 1.2) * (A + B - C) the sequence of operation is

    • Options
    • A. + + + - * =
    • B. * + + + - =
    • C. + + - * + =
    • D. - + + + * =
    • Discuss
    • 10. A digital voltmeter has a read out range from 0 to 999 counts. If the full scale reading is 9.999 V, the resolution is

    • Options
    • A. 1 V
    • B. 0.01 V
    • C. 1 mV
    • D. 1 ?V
    • Discuss


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