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. |
*/*_The minority carrier concentration is largely a function of? |
| A. | Forward biasing voltage |
| B. | Reverse biasing voltage |
| C. | Temperature |
| D. | The amount of doping |
| Answer» D. The amount of doping | |
| 2. |
*/*_The number of atoms per unit cell in B.C.C. structure is? |
| A. | 1 |
| B. | 2 |
| C. | 4 |
| D. | 8 |
| Answer» C. 4 | |
| 3. |
%_The number of atoms per unit cell in B.C.C. structure is_% |
| A. | 1 |
| B. | 2 |
| C. | 4 |
| D. | 8 |
| Answer» C. 4 | |
| 4. |
_ The conductivity of a metal is determined by$? |
| A. | The electronic concentration and the mobility of the free electrons |
| B. | The number of valence electrons per atom |
| C. | Either A or B |
| D. | None of the above |
| Answer» B. The number of valence electrons per atom | |
| 5. |
_ In thermocouples which of the following pairs is commonly used ?$? |
| A. | Copper-constantan |
| B. | Aluminium-tin |
| C. | Silver-German silver |
| D. | Iron-steel |
| Answer» B. Aluminium-tin | |
| 6. |
_ Which of the following high resistance materials has the highest operating temperature ?$? |
| A. | Kanthal |
| B. | Manganin |
| C. | Nichrome |
| D. | Eureka |
| Answer» B. Manganin | |
| 7. |
_ The converse of hardness is known as$? |
| A. | Malleability |
| B. | Toughness |
| C. | Softness |
| D. | None of the above |
| Answer» D. None of the above | |
| 8. |
_ At transition temperature the value of critical field is$? |
| A. | Zero |
| B. | Negative real value |
| C. | Positive real value |
| D. | Complex value |
| Answer» B. Negative real value | |
| 9. |
_ The photo-electric effect occurs only when the incident light has more than a certain critical$? |
| A. | Intensity |
| B. | Speed |
| C. | Frequency |
| D. | Wave length |
| Answer» D. Wave length | |
| 10. |
_ A good electric contact material should have all of the following properties except$? |
| A. | High resistivity |
| B. | High resistance to corrosion |
| C. | Good thermal conductivity |
| D. | High melting point |
| Answer» B. High resistance to corrosion | |
| 11. |
_________ is a hard solder.__ |
| A. | Tin-lead |
| B. | Tin-silver-lead |
| C. | Copper-zinc |
| D. | None of the above |
| Answer» D. None of the above | |
| 12. |
__Mercury as an electric contact material is__ |
| A. | A liquid |
| B. | A metal |
| C. | A metal liquid |
| D. | A gas |
| Answer» D. A gas | |
| 13. |
__A perfect conductor has__ |
| A. | Zero conductivity |
| B. | Unity conductivity |
| C. | Infinite conductivity |
| D. | None of the above |
| Answer» D. None of the above | |
| 14. |
__The conduction of electricity, in semiconductors, takes place due to movement of__ |
| A. | Positive ions only |
| B. | Negative ions only |
| C. | Positive and negative ions |
| D. | Electrons and holes |
| Answer» E. | |
| 15. |
__Which of the following is a semiconductor material ?__ |
| A. | Phosphorous |
| B. | Rubber |
| C. | Silicon |
| D. | Aluminium |
| Answer» D. Aluminium | |
| 16. |
__Which of the following materials does not have covalent bonds ?__ |
| A. | Organic polymers |
| B. | Silicon |
| C. | Metals |
| Answer» D. | |
| 17. |
__Which of the following materials is used for making coils of standard resistances ?__ |
| A. | Copper |
| B. | Nichrome |
| C. | Platinum |
| D. | Manganin |
| Answer» E. | |
| 18. |
__The tiny block formed by the arrangement of a small group of atoms is called the__ |
| A. | Unit cell |
| B. | Space lattice |
| C. | Either A or B |
| D. | None of the above |
| Answer» B. Space lattice | |
| 19. |
Which of the following is an advantage of stranded conductor over equivalent single conductor ?$? |
| A. | Less liability to kink |
| B. | Greater flexibility |
| C. | Less liability to break |
| D. | All of the above |
| Answer» E. | |
| 20. |
Due to which of the following reasons aluminium does not corrode in atmosphere ?$? |
| A. | Aluminium is a noble metal |
| B. | Atmospheric oxygen can only diffuse very slowly through the oxide layer which is formed on the surface of aluminium |
| C. | No reaction with oxygen occurs ft Any of the above |
| D. | All of the above |
| Answer» C. No reaction with oxygen occurs ft Any of the above | |
| 21. |
Thermocouples are mainly used for the measurement of$? |
| A. | Temperature |
| B. | Resistance |
| C. | Eddy currents |
| D. | Coupling co-efficient |
| Answer» B. Resistance | |
| 22. |
In graphite, bonding is$? |
| A. | Covalent |
| B. | Metallic |
| C. | Vander Waals |
| D. | Vander Waals and covalent |
| Answer» E. | |
| 23. |
Carbon electrodes are not used in$? |
| A. | GLS lamps |
| B. | Electric arc furnace |
| C. | Dry cells |
| D. | Cinema projectors |
| Answer» B. Electric arc furnace | |
| 24. |
The impurity atoms is semiconductors$? |
| A. | Inject more charge carriers |
| B. | Reduce the energy gap |
| C. | Increase the kinetic energy of valence electrons |
| D. | All of the above |
| Answer» C. Increase the kinetic energy of valence electrons | |
| 25. |
_________ is most commonly used for making magnetic recording tape$? |
| A. | Silver nitrate |
| B. | Ferric oxide |
| C. | Small particles of iron |
| D. | Silicon-iron |
| Answer» C. Small particles of iron | |
| 26. |
The resistivity of a metal is a function of temperature because$? |
| A. | The amplitude of vibration of the atoms varies with temperature |
| B. | The electron density varies with temperature |
| C. | The electron gas density varies with temperature |
| D. | None of the above |
| Answer» B. The electron density varies with temperature | |
| 27. |
The conductivity of a conductor can be increased by$? |
| A. | Decreasing its temperature |
| B. | Increasing its temperature |
| C. | Decreasing its vibration |
| D. | Increasing its vibration |
| Answer» B. Increasing its temperature | |
| 28. |
The metal having the lowest temperature coefficient of resistance is$? |
| A. | Gold |
| B. | Copper |
| C. | Aluminium |
| D. | Kanthal |
| Answer» B. Copper | |
| 29. |
The co-ordination number of a simple cubic structure is$? |
| A. | |
| B. | 2 |
| C. | 4 |
| D. | 6 |
| Answer» D. 6 | |
| 30. |
_______ has zero temperature co-efficient of resistance.$? |
| A. | Aluminium |
| B. | Carbon |
| C. | Porcelain |
| D. | Manganin |
| Answer» E. | |
| 31. |
Most of the common metals have _________ structure.$? |
| A. | Linear |
| B. | Hexagonal |
| C. | Orthorhombic |
| D. | Cubic |
| Answer» E. | |
| 32. |
An H.R.C. fuse is$? |
| A. | A ceramic body having metal and caps |
| B. | A wire of platinum |
| C. | A heavy cross-section of copper or aluminium |
| D. | A ceramic tube having carbon rod inside it |
| Answer» B. A wire of platinum | |
| 33. |
Piezoelectric materials serve as a source of ________ .$? |
| A. | Resonant waves |
| B. | Musical waves |
| C. | Microwaves |
| D. | Ultrasonic waves |
| Answer» E. | |
| 34. |
Low resistivity materials are used in$? |
| A. | Transformer, motor and generator windings |
| B. | Transmission and distribution lines |
| C. | House wiring |
| D. | All above applications |
| Answer» E. | |
| 35. |
Piezoelectric materials serve as a source of ________ .? |
| A. | Resonant waves |
| B. | Musical waves |
| C. | Microwaves |
| D. | Ultrasonic waves |
| Answer» E. | |
| 36. |
Due to which of the following fact, in India, aluminium is replacing copper ? |
| A. | Aluminium is more ductile and malleable than copper |
| B. | Aluminium is available in plenty, cheaper and lighter than copper |
| C. | Aluminium has lower resistivity than that of copper |
| D. | Aluminium has less temperature co-efficient than copper |
| Answer» C. Aluminium has lower resistivity than that of copper | |
| 37. |
Addition of 0.3 to 4.5% silicon to iron __________ the electrical resistivity of iron. |
| A. | Increases |
| B. | Decreases |
| C. | Does not change |
| D. | Change |
| Answer» B. Decreases | |
| 38. |
Due to which of the following reasons copper and aluminium are not used for heating elements ? |
| A. | Both have great tendency for oxidation |
| B. | Both have low melting point |
| C. | Very large length of wires will be required |
| D. | All of the above |
| Answer» E. | |
| 39. |
The formula __________ determines the number of electrons that can be accommodated in any level. |
| A. | 2n2 |
| B. | 4n2 |
| C. | 2n3 |
| D. | 4ns |
| Answer» B. 4n2 | |
| 40. |
Substances whose specific resistance abruptly decreases at very low temperature are called |
| A. | Insulators |
| B. | Conductors |
| C. | Semiconductors |
| D. | Superconductors |
| Answer» E. | |
| 41. |
Is a negatively charged particle present in an atom. |
| A. | Proton |
| B. | Neutron |
| C. | Electron |
| D. | None of the above |
| Answer» D. None of the above | |
| 42. |
Super conductivity can be destroyed by |
| A. | Adding impurities |
| B. | Reducing temperatures |
| C. | Application of magnetic field |
| D. | Any of the above |
| Answer» D. Any of the above | |
| 43. |
The current due to electron flow in conduction band is the hole current in valence band. |
| A. | Equal to |
| B. | Less than |
| C. | Greater than |
| D. | Any of the above |
| Answer» D. Any of the above | |
| 44. |
Copper, even though costly, finds use in the windings of electrical machines because |
| A. | Copper points offer low contact resistance |
| B. | Copper can be easily soldered and welded |
| C. | Copper windings are less bulky and the machines become compact |
| D. | All of the above |
| Answer» E. | |
| 45. |
Spark plug makes use of which of the following materials for insulation ? |
| A. | Porcelain |
| B. | Slate |
| C. | Asbestos |
| D. | Glass |
| Answer» B. Slate | |
| 46. |
On which of the following factors does the resistivity of a material depend ? |
| A. | Resistance of the conductor |
| B. | Area of the conductor section |
| C. | Length of the conductor |
| D. | All of the above |
| Answer» E. | |
| 47. |
The carbon percentage is least in |
| A. | low carbon steel |
| B. | wrought iron |
| C. | cast iron |
| D. | malleable iron |
| Answer» C. cast iron | |
| 48. |
For a hole which of the following statements is incorrect ? |
| A. | Holes can exist in certain semiconductors only |
| B. | Holes can exist in any material including conductors |
| C. | Holes may constitute an electric current |
| D. | Holes can be considered as a net positive charge |
| Answer» C. Holes may constitute an electric current | |
| 49. |
__________ is the main constituent of glass |
| A. | Fe203 |
| B. | Si02 |
| C. | AI2O3 |
| D. | B2O3 |
| Answer» C. AI2O3 | |
| 50. |
Carbon bearings are used under which of the following conditions ? |
| A. | Where lubrication is difficult or im-possible |
| B. | Where corrosive chemical action exists |
| C. | Where high temperature exists |
| D. | All of the above |
| Answer» E. | |