MCQOPTIONS
Saved Bookmarks
MCQOPTIONS
This section includes 657 Mcqs, each offering curated multiple-choice questions to sharpen your Testing Subject knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Which of the following can be operated with positive as well as negative gate voltage? |
| A. | JFET |
| B. | Both JFET and MOSFET |
| C. | MOSFET |
| D. | Neither JFET nor MOSFET |
| Answer» D. Neither JFET nor MOSFET | |
| 2. |
The reverse breakdown voltage of a diode depends on the extent of doping. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 3. |
The turn off time of a bipolar transistor is about |
| A. | 0.5 ns |
| B. | 10 ns |
| C. | 70 ns |
| D. | 150 ns |
| Answer» D. 150 ns | |
| 4. |
Hystresis loss least depends on |
| A. | frequency |
| B. | magnetic field intensity |
| C. | volume of the material |
| D. | grain orientation of material |
| Answer» E. | |
| 5. |
In a bipolar transistor, emitter efficiency is about |
| A. | 0.99 |
| B. | 0.9 |
| C. | 0.8 |
| D. | 0.7 |
| Answer» B. 0.9 | |
| 6. |
For signal diodes the PIV rating is usually in the range |
| A. | 1 V to 10V |
| B. | 10 V to 30V |
| C. | 30 V to 150V |
| D. | 150 V to 400V |
| Answer» D. 150 V to 400V | |
| 7. |
The potential of suppressor grid (with respect to cathode) is usually |
| A. | zero |
| B. | negative |
| C. | positive |
| D. | zero or positive |
| Answer» B. negative | |
| 8. |
If the atomic number of germanium is 32, the number of electrons in the outer most shell will be |
| A. | 2 |
| B. | 3 |
| C. | 4 |
| D. | 6 |
| Answer» D. 6 | |
| 9. |
Dielectric loss due to polarisation occurs in |
| A. | bipolar dielectrics |
| B. | non-metallic dielectrics |
| C. | liquid dielectrics |
| D. | all of the above |
| Answer» B. non-metallic dielectrics | |
| 10. |
A metal loses electrons at room temperature. |
| A. | True |
| B. | False |
| Answer» C. | |
| 11. |
Consider the following statement associated with bipolar junction transistor and JFET The former has higher input impedance than the laterThe former has higher frequency stability than the laterThe later has lower noise figure than the formerThe later has higher power rating than the former. Of these statements |
| A. | 1 and 2 are correct |
| B. | 2 and 3 are correct |
| C. | 3 and 4 are correct |
| D. | 1 and 4 are correct |
| Answer» C. 3 and 4 are correct | |
| 12. |
If the energy gap of a semiconductor is 1.1 eV, then it would be |
| A. | opaque to visible light |
| B. | transparent to visible light |
| C. | transparent to ultraviolet radiation |
| D. | transparent to infrared radiation |
| Answer» B. transparent to visible light | |
| 13. |
The voltage at which Avalanche occurs is known as |
| A. | cut in voltage |
| B. | barrier voltage |
| C. | breakdown voltage |
| D. | depletion voltage |
| Answer» D. depletion voltage | |
| 14. |
The resistivity of a semiconductor |
| A. | increases as the temperature increases |
| B. | decreases as the temperature increases |
| C. | remains constant even when temperature varies |
| D. | none of the above |
| Answer» C. remains constant even when temperature varies | |
| 15. |
In intrinsic semiconductor the increase in conductivity per degree increase in temperature is about |
| A. | 2% |
| B. | 6% |
| C. | 15% |
| D. | 25% |
| Answer» C. 15% | |
| 16. |
The ripple factor for a bridge rectifier is |
| A. | 0.406 |
| B. | 1.21 |
| C. | 1.11 |
| D. | 2.22 |
| Answer» C. 1.11 | |
| 17. |
In the BJT amplifier shown in the figure is the transistor is biased in the forward active region. Putting a capacitor across RE will |
| A. | decrease the voltage gain and decrease the I/P impedance |
| B. | increase the voltage gain and decrease the I/P Impedance |
| C. | decrease the voltage gain and Increase the I/P impedance |
| D. | none of the above |
| Answer» C. decrease the voltage gain and Increase the I/P impedance | |
| 18. |
Consider the following statements.The functions of an oxide layer in an IC device is to mask against diffusion or ion implantinsulate the surface electricallyincrease the melting point of siliconproduce a chemically stable protective layer of these statements. |
| A. | 1, 2, 3 |
| B. | 1, 3, 4 |
| C. | 2, 3, 4 |
| D. | 1, 2, 4 |
| Answer» E. | |
| 19. |
In a centre tap full wave rectifier, 50 V is the peak voltage between the centre tap and one of the ends of the secondary. The maximum voltage across the reverse biased diode will be |
| A. | 100 V |
| B. | 72 V |
| C. | 50 V |
| D. | 38 V |
| Answer» B. 72 V | |
| 20. |
Assertion (A): A BJT can be used as a switch. Reason (R): In forward active mode emitter base junction is forward biased and base collector junction is reverse biased. |
| A. | Both A and R are true and R is correct explanation of A |
| B. | Both A and R are true but R is not a correct explanation of A |
| C. | A is true but R is false |
| D. | A is false but R is true |
| Answer» C. A is true but R is false | |
| 21. |
The forbidden energy gap for germanium is |
| A. | 0.12 eV |
| B. | 0.32 eV |
| C. | 0.72 eV |
| D. | 0.92 eV |
| Answer» D. 0.92 eV | |
| 22. |
The concentration of minority carriers in an extrinsic semiconductor under equilibrium is |
| A. | directly proportional to the doping concentration |
| B. | inversely proportional to doping concentration |
| C. | directly proportional to intrinsic concentration |
| D. | inversely proportional to the intrinsic concentration |
| Answer» C. directly proportional to intrinsic concentration | |
| 23. |
The mean life time of the minority carriers is in the range of a few |
| A. | seconds |
| B. | milli seconds |
| C. | micro seconds |
| D. | nano seconds |
| Answer» E. | |
| 24. |
Choose the correct match for input resistance of various amplifier configurations shown below configuration.CB : Common Base LO : LowCC : Common Collector MO : moderateCE : Common EmitterHI: High |
| A. | CB-LO, CC-MO, CE-HI |
| B. | CB-LO, CC-HI, CE-MO |
| C. | CB-MO, CC-HI, CE-LO |
| D. | CB-HI, CC-LO, CE-MO |
| Answer» C. CB-MO, CC-HI, CE-LO | |
| 25. |
A long specimen of P type semiconductor material |
| A. | is + vely charged |
| B. | is electrically neutral |
| C. | has an electric field directed along its length |
| D. | acts as a dipole |
| Answer» C. has an electric field directed along its length | |
| 26. |
An inductor filter has a ripple that __________ with load resistance and consequently is used only with relatively __________ load currents. |
| A. | decreases, low |
| B. | decreases, high |
| C. | increases, low |
| D. | increases, high |
| Answer» E. | |
| 27. |
Electric breakdown strength of a material depends on its |
| A. | composition |
| B. | moisture content |
| C. | thickness |
| D. | all of the above |
| Answer» E. | |
| 28. |
The atomic weight of an atom is determined by |
| A. | the number of protons |
| B. | the number of neutrons |
| C. | the number of protons and neutrons |
| D. | the number of electrons and protons |
| Answer» D. the number of electrons and protons | |
| 29. |
The minimum charge carried by an ion is |
| A. | zero |
| B. | equal to the change of an electron |
| C. | equal to the change of a pair of electrons |
| D. | equal to the change of electrons left in the atom |
| Answer» C. equal to the change of a pair of electrons | |
| 30. |
Which statement is false as regards holes |
| A. | Holes exist in conductors as well as semiconductors |
| B. | Holes constitute positive charges |
| C. | Holes exist only in semiconductors |
| D. | Holes and electrons recombine |
| Answer» B. Holes constitute positive charges | |
| 31. |
Photo electric emission can occur only if |
| A. | wave length of incident radiation is equal to threshold value |
| B. | wave length of incident radiation is less than threshold value |
| C. | frequency of incident radiation is less than threshold frequency |
| D. | none of the above |
| Answer» C. frequency of incident radiation is less than threshold frequency | |
| 32. |
The reverse saturation current of a diode does not depend on temperature. |
| A. | True |
| B. | False |
| Answer» C. | |
| 33. |
The drain characteristics of JFET in operating region, are |
| A. | inclined upwards |
| B. | almost flat |
| C. | inclined downwards |
| D. | inclined upwards or downwards |
| Answer» C. inclined downwards | |
| 34. |
The value of a in a transistor |
| A. | is always equal to 1 |
| B. | is less than 1 but more than 0.9 |
| C. | is about 0.4 |
| D. | is about 0.1 |
| Answer» C. is about 0.4 | |
| 35. |
In a piezoelectric crystal, application of a mechanical stress would produce |
| A. | plastic deformation of the crystal |
| B. | magnetic Dipoles in the crystal |
| C. | electric polarization in the crystal |
| D. | shift in the Fermi level |
| Answer» D. shift in the Fermi level | |
| 36. |
As temperature increases |
| A. | the forbidden energy gap in silicon and germanium increase |
| B. | the forbidden energy gap in silicon and germanium decrease |
| C. | the forbidden energy gap in silicon decreases while that in germanium decreases |
| D. | the forbidden energy gap in silicon increases while that in germanium decreases |
| Answer» C. the forbidden energy gap in silicon decreases while that in germanium decreases | |
| 37. |
When a reverse bias is applied to a p-n junction, the width of depletion layer. |
| A. | decreases |
| B. | increases |
| C. | remains the same |
| D. | may increase or decrease |
| Answer» C. remains the same | |
| 38. |
For BJT transistor. The maximum power dissipation is specified as 350 mW if ambient temperature is 25 C. If ambient temperature is 60 C the maximum power dissipation should be limited to about |
| A. | 100 mW |
| B. | 250 mW |
| C. | 450 mW |
| D. | 600 mW |
| Answer» C. 450 mW | |
| 39. |
Which of the following devices has a silicon dioxide layer? |
| A. | NPN transistor |
| B. | Tunnel diode |
| C. | JFET |
| D. | MOSFET |
| Answer» E. | |
| 40. |
In a bipolar junction transistor the base region is made very thin so that |
| A. | recombination in base region is minimum |
| B. | electric field gradient in base is high |
| C. | base can be easily fabricated |
| D. | base can be easily biased |
| Answer» B. electric field gradient in base is high | |
| 41. |
Which of the following has highest conductivity? |
| A. | Silver |
| B. | Aluminium |
| C. | Tungsten |
| D. | Platinum |
| Answer» B. Aluminium | |
| 42. |
The concentration of minority carriers in a semiconductor depends mainly on |
| A. | the extent of doping |
| B. | temperature |
| C. | the applied bias |
| D. | none of the above |
| Answer» C. the applied bias | |
| 43. |
Compared to bipolar junction transistor, a JFET has |
| A. | lower input impedance |
| B. | high input impedance and high voltage gain |
| C. | higher voltage gain |
| D. | high input impedance and low voltage gain |
| Answer» E. | |
| 44. |
A diode is operating in forward region and the forward voltage and current are v = 3 + 0.3 sin t (volts) and i = 5 + 0.2 sin t (mA). The average power dissipated is |
| A. | 15 mW |
| B. | about 15 mW |
| C. | 1.5 mW |
| D. | about 1.5 mW |
| Answer» C. 1.5 mW | |
| 45. |
The amount of photoelectric emission current depends on the frequency of incident light. |
| A. | True |
| B. | False |
| Answer» C. | |
| 46. |
When a p-n junction is forward biased |
| A. | the width of depletion layer increases |
| B. | the width of depletion layer decreases |
| C. | the majority carriers move away from the junction |
| D. | the current is very small |
| Answer» C. the majority carriers move away from the junction | |
| 47. |
The carriers of n channel JFET are |
| A. | free electrons and holes |
| B. | holes |
| C. | free electrons or holes |
| D. | free electrons |
| Answer» E. | |
| 48. |
The depletion layer around p-n junction in JFET consists of |
| A. | hole |
| B. | electron |
| C. | immobile charges |
| D. | none of the above |
| Answer» D. none of the above | |
| 49. |
Junction temperature is always the same as room temperature. |
| A. | True |
| B. | False |
| Answer» C. | |
| 50. |
If the reverse voltage across a p-n junction is increased three times, the junction capacitance |
| A. | will decrease |
| B. | will increase |
| C. | will decrease by an approximate factor of about 2 |
| D. | will increase by an approximate factor of about 2 |
| Answer» D. will increase by an approximate factor of about 2 | |