MCQOPTIONS
Saved Bookmarks
MCQOPTIONS
This section includes 69 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Engineering Questions knowledge and support exam preparation. Choose a topic below to get started.
| 51. |
High resistivity materials are used in_____________? |
| A. | precision instruments |
| B. | heating elements |
| C. | motor starters |
| D. | incandescent lamps |
| E. | all of the above |
| Answer» F. | |
| 52. |
___________ has the best damping properties? |
| A. | Diamond |
| B. | High speed steel |
| C. | Mild steel |
| D. | Cast iron |
| Answer» E. | |
| 53. |
For germanium the forbidden energy gap is_______________? |
| A. | 0.15 eV |
| B. | 0.25 eV |
| C. | 0.5eV |
| D. | 0.7eV |
| Answer» E. | |
| 54. |
For a particular material the Hall coefficient was found to be zero. The material is______________? |
| A. | insulator |
| B. | metal |
| C. | intrinsic semiconductor |
| D. | none of the above |
| Answer» C. intrinsic semiconductor | |
| 55. |
Effect of moisture on the insulating materials is to________________? |
| A. | decrease dielectric constant |
| B. | decrease dielectric strength |
| C. | decrease insulation resistance |
| D. | increase dielectric loss |
| E. | all of the above |
| Answer» F. | |
| 56. |
Due to which of the following factors the brush wear rate is altered ? |
| A. | Speed of the machine |
| B. | Contact pressure |
| C. | Surface conditions of brush and commutator |
| D. | Excessive sparking |
| E. | All of the above |
| Answer» F. | |
| 57. |
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. | |
| 58. |
Constantan contains_______________? |
| A. | silver and tin |
| B. | copper and tungsten |
| C. | tungsten and silver |
| D. | copper and nickel |
| Answer» E. | |
| 59. |
Commonly used conducting materials are_____________? |
| A. | copper |
| B. | aluminium |
| C. | both (A) and (B) |
| D. | copper and silver |
| E. | platinum and gold |
| Answer» D. copper and silver | |
| 60. |
Carbon rods are used in wet and dry cells because_____________? |
| A. | carbon rod serves as conductor |
| B. | carbon can resist the attack of battery acid |
| C. | both (A) and (B) |
| D. | either (A) or (B) |
| Answer» D. either (A) or (B) | |
| 61. |
Carbon resistors are used extensively because they are____________? |
| A. | easy to make |
| B. | compact |
| C. | inexpensive |
| D. | all of the above reasons |
| Answer» E. | |
| 62. |
Carbon electrodes are not used in_______________? |
| A. | GLS lamps |
| B. | electric arc furnace |
| C. | dry cells |
| D. | cinema projectors |
| Answer» B. electric arc furnace | |
| 63. |
By increasing impurity content in the metal alloy the residual resistivity always_____________? |
| A. | decreases |
| B. | increases |
| C. | remains constant |
| D. | becomes temperature independent |
| Answer» C. remains constant | |
| 64. |
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 | |
| 65. |
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 | |
| 66. |
Addition of 0.3 to 4.5% silicon to iron ________ the electrical resistivity of iron? |
| A. | increases |
| B. | decreases |
| C. | does not change |
| Answer» B. decreases | |
| 67. |
A perfect conductor has_____________? |
| A. | zero conductivity |
| B. | unity conductivity |
| C. | infinite conductivity |
| D. | none of the above |
| Answer» D. none of the above | |
| 68. |
A highly conductive material must have___________? |
| A. | highest conductivity |
| B. | lowest temperature co-efficient |
| C. | good mechanical strength |
| D. | good corrosion resistance |
| E. | all of the above |
| Answer» F. | |
| 69. |
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 | |