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  • Question

  • In a semiconductor material. The hole concentration is found to be 2 x 2.5 x 1015 cm-3. If mobility of carriers is 0.13 m2/ v-s. Then find the current density if electric field intensity is 3.62 x 10-19


  • Options
  • A. 7.6237 x 10-4 A/cm2
  • B. 7.6237 x 10-5 A/cm2
  • C. 7.6237 x 10-3 A/cm2
  • D. none of these

  • Correct Answer
  • 7.6237 x 10-4 A/cm2 

    Explanation
    Current density J = ?E

    Where ? = conductivity

    Given -> ? = 0.13 m2/v-s = 0.13 x 104 cm2/V sec

    P = 2.25 x 1015/cm3

    We have, ? ni = 1.5 x 1010

    Also n.p. =In a semiconductor material. The hole concentration is found to be 2 x 2.5 x 1015 cm-3. If mobility

    ? n = In a semiconductor material. The hole concentration is found to be 2 x 2.5 x 1015 cm-3. If mobility /p

    In a semiconductor material. The hole concentration is found to be 2 x 2.5 x 1015 cm-3. If mobility

    In a semiconductor material. The hole concentration is found to be 2 x 2.5 x 1015 cm-3. If mobility

    = (1.6 x 10-19 x 0.13 x 104 x 2.25 x 1015) xIn a semiconductor material. The hole concentration is found to be 2 x 2.5 x 1015 cm-3. If mobility

    = (0.468) (4.5 x 1015)

    ? = 2.106 x 1015 ?/cm

    J = ?E

    ? Current density = 2.106 x 1015 x 3.620 x 10-19

    = 7.6237 x 10-4 A/m2.

    Exam Questions Papers problems

    Search Results

    • 1. A certain 8 bit uniform quantization PCM system can accommodate a signal ranging from - 1 V to + V. The rms value of the signal is V . The signal to quantization noise ratio is:

    • Options
    • A. 30 dB
    • B. 46.91 dB
    • C. 40 dB
    • D. 49.92 dB
      • Discuss
    • 2. A unity-feedback control system has the open loop transfer function . If the input system is a unit ramp, the steady state error will be

    • Options
    • A. 0
    • B. 0.5
    • C. 2
    • D. infinity
      • Discuss
    • 3. Consider the amplitude modulated (AM) signal Ac cos ?ct + 2 cos ?mt cos ?ct For demodulating the signal using envelope detector, the minimum value of Ac should be

    • Options
    • A. 2
    • B. 1
    • C. 0.5
    • D. 0
      • Discuss
    • 4. The amplifier circuit shown below uses a silicon transistor. The capacitors Cc and CE can be assumed to be short at signal frequency and the effect of output resistance r0 can be ignored. If CE is disconnected from the circuit, which one of the following statements is TRUE?

    • Options
    • A. The input resistance Ri increases and the magnitude of voltage gain Av decreases
    • B. The input resistance Ri decreases and the magnitude of voltage gain Av decreases
    • C. Both input resistance Ri and the magnitude of voltage gain Av decrease
    • D. Both input resistance Ri and the magnitude of voltage gain Av increase
      • Discuss
    • 5. In the following non planar graph number of independent loop equations are

    • Options
    • A. 8
    • B. 12
    • C. 7
    • D. 5
      • Discuss
    • 6. The analog signal given below is sampled at 1200 samples per second. m(t) = 2 sin 120 pt + 3 sin 240 pt + 4 sin 360 pt + 5 sin 480 pt + 6 sin 600 pt + 7 sin 720 pt. The folding (maximum) frequency is __________ .

    • Options
    • A. 300 Hz
    • B. 360 Hz
    • C. 600 Hz
    • D. 480 Hz
      • Discuss
    • 7. A rectangular waveguide, in dominant TE mode, has dimensions 10 cm x 15 cm. The cut off frequency is

    • Options
    • A. 10 GHz
    • B. 1 GHz
    • C. 15 GHz
    • D. 25 GHz
      • Discuss
    • 8. A noiseless 3 KHz channel can transmit binary at the rate __________ .

    • Options
    • A. 12000 bps
    • B. 10000 bps
    • C. 6000 bps
    • D. 3000 bps
      • Discuss
    • 9. Radiation resistance of an antenna is 54 ? and loss resistance is 6 ?. If antenna has power gain of 10, then directivity is:

    • Options
    • A. 9
    • B. 11.11
    • C. data not sufficient
    • D. 10
      • Discuss
    • 10. Consider a unity feedback control system with open-loop transfer function The steady state error of the system due to a unity step input is :

    • Options
    • A. zero
    • B. K
    • C. 1/K
    • D. infinite
      • Discuss

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