In the name of ALLAH, the most beneficient, the most merciful

Circuit Theory (PHY301)

Multiple Choice Questions (MCQs)

Objective Questions

  1. A transformer may consists of ________.

    1. one winding
    2. two windings
    3. two or more than two windings
    4. no winding
  2. When the turn ratio of a transformer is 10 and primary ac voltage is 6v, the secondary voltage is ________.

    1. 36v
    2. 6v
    3. 60v
    4. 0.6v
  3. For a P-N junction under forward bias

    1. more forward current flows
    2. no forward current flows
    3. more reverse current flows
    4. infinite reverse current flows
  4. Using exponential model for a diode that conducts at 1mA with n = 2, the change in current due to change of voltage by 5mv will be

    1. 0.4mA
    2. 0.8mA
    3. 3mA
    4. 0.11mA
  5. Diode small signal resistance rd at bias current of 5mA for n = 1 will be

    1. 10 ohms
    2. 8 ohms
    3. 5 ohms
    4. 2.5 ohms
  6. There is a ________ energy gap between valence and conduction band.

    1. forbidden
    2. permitted
  7. Which transformer gives less voltage at secondary as compared to primary?

    1. islated transformer
    2. step up transformer
    3. step down transformer
    4. all transformer
  8. True or false, hole current is opposit of electron current?

    1. True
    2. False
  9. The primary and secondary winding of transformer are

    1. physically touched
    2. physically isolated
    3. touched with conductor
    4. largely separated
  10. Analysing the farward biase region of junction diode , the value of constant voltage,VT is ________.

    1. 25.02V
    2. 10mV
    3. 25.02mV
    4. 5Mv
  11. A transformer will be out of phase when ________.

    1. output voltage is 0 degree out of phase with input voltage
    2. output voltage is 180 degree out of phase with input voltage
    3. output voltage is 360 degree out of phase with input voltage
    4. output voltage is same as input voltage
  12. In a P- type semiconductor material, the majority carriers are ________.

    1. Holes
    2. Electrons
    3. Ions
    4. Protons
  13. If 10w of power is applied to primary of an ideal transformer with a turn ratio of 5, the power delivered to the secondary load is

    1. 25w
    2. 50w
    3. 0.5
    4. 10w
  14. If a silicon diode conducts at 2mA and whose n = 1, the slope of diode will be at

    1. 1/25 ohms
    2. 1/2 ohms
    3. 2/25 ohms
    4. 2 ohms
  15. There is no voltage drop across diode when forward biased, in case of

    1. ideal diode model
    2. practical diode model
  16. Secondary voltage is greater in magnitude as compared to primary voltage in a ________.

    1. step down transformer
    2. step up transformer
    3. isolated transformer
    4. simple transformer
  17. In an N-type semiconductor material, the majority carrier are

    1. holes
    2. electron
    3. ions
    4. protons
  18. If turn ratio of a transformer is 5 and secondary current is 2A, the primary current is ________.

    1. 2.5A
    2. 10A
    3. 0.4A
    4. 7A
  19. Addition of impuritirs in semiconductor material to produce more current is called

    1. intrinsic
    2. dopping
    3. bonding
    4. excitation
  20. The width of the depletion layer of a junction

    1. decreases with light doping
    2. increases with heavy doping
    3. under reverse bias
    4. is increased under reverse bias