MCQOPTIONS
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MCQOPTIONS
This section includes 286 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Engineering materials knowledge and support exam preparation. Choose a topic below to get started.
| 151. |
Metallic bonding is due to: |
| A. | sharing of electrons between adjacent atoms |
| B. | over-lapping of electron clouds |
| C. | attraction between ion cores |
| D. | attraction between ion cores and electrons |
| Answer» E. | |
| 152. |
The electrostatic nature of ionic bond makes it: |
| A. | directional |
| B. | non-directional |
| C. | weak |
| D. | applicable to group IV elements |
| Answer» C. weak | |
| 153. |
The relaxation time ( ) in a perfect dielectric is: |
| A. | 0 |
| B. | 1 |
| C. | 1 < < |
| D. | |
| Answer» C. 1 < < | |
| 154. |
The resistivity of all normal metals: |
| A. | tends to zero |
| B. | tends to constant value |
| C. | first decreases and then increases as temperature is lowered |
| D. | None of the above |
| Answer» B. tends to constant value | |
| 155. |
Resistivity of electrical conductors is most affected by: |
| A. | temperature |
| B. | pressure |
| C. | humidity |
| D. | All of these |
| Answer» B. pressure | |
| 156. |
The dielectric strength of impregnated paper is: |
| A. | 40 50 kV/cm |
| B. | 200 300 kV/cm |
| C. | 500 600 kV/cm |
| D. | 1000 kV/cm and above |
| Answer» B. 200 300 kV/cm | |
| 157. |
The maximum working voltage for a paper capacitor is: |
| A. | 500 V |
| B. | 1000 V |
| C. | 230 V |
| D. | 5000 V |
| Answer» C. 230 V | |
| 158. |
Covalent bond-energy in Ge is approximately equal to: |
| A. | 7.4 eV |
| B. | 31 eV |
| C. | 3.4 eV |
| D. | 20.4 eV |
| Answer» B. 31 eV | |
| 159. |
Which of the following figure represents a ferrimagnetic material? |
| A. | Fig. A |
| B. | Fig. B |
| C. | Fig. C |
| D. | Fig. D |
| Answer» C. Fig. C | |
| 160. |
Material with lowest temperature coefficient: |
| A. | Aluminium |
| B. | Copper |
| C. | Gold |
| D. | Silver |
| Answer» D. Silver | |
| 161. |
Material with highest resistivity: |
| A. | Kanthal |
| B. | Nichrome |
| C. | Manganin |
| D. | Tantenum |
| Answer» B. Nichrome | |
| 162. |
In photoelectron emission, the threshold frequency is defined as the: |
| A. | minimum frequency at which field emission begins |
| B. | lowest frequency at which photoemission of electron starts |
| C. | maximum frequency at which photoemission of electron stops |
| D. | None of these |
| Answer» B. lowest frequency at which photoemission of electron starts | |
| 163. |
The connecting leads of an IC are made of: |
| A. | Silicon |
| B. | Germanium |
| C. | Aluminium |
| D. | Carbon |
| Answer» D. Carbon | |
| 164. |
Relative permeability of a paramagnetic material is: |
| A. | one |
| B. | less than one |
| C. | more than one |
| D. | several hundreds |
| Answer» D. several hundreds | |
| 165. |
Schottky effect describes: |
| A. | effect of intensive electric field on the rate of electron emission from a cathode |
| B. | current in temperature limited region |
| C. | current in space charge region |
| D. | None of these |
| Answer» B. current in temperature limited region | |
| 166. |
Figure given below represents: |
| A. | Paramagnetic |
| B. | Diamagnetic |
| C. | Ferrimagnetic |
| D. | Antiferromagnetic |
| Answer» E. | |
| 167. |
Magnetic recording tape is most commonly made from: |
| A. | small particles of iron |
| B. | silicon iron |
| C. | ferric oxide |
| D. | None of these |
| Answer» D. None of these | |
| 168. |
Stainless steels are alloys of: |
| A. | Fe and Ni |
| B. | Fe, Cr and Ni |
| C. | Fe, Cr and Mo |
| D. | None of these |
| Answer» C. Fe, Cr and Mo | |
| 169. |
Materials which are good conductors of both heat and electricity are: |
| A. | Metals |
| B. | Ceramics |
| C. | Polymers |
| D. | None of these |
| Answer» B. Ceramics | |
| 170. |
Ionic bonding in solids depends primarily on: |
| A. | Vander Waals forces |
| B. | electrical dipoles |
| C. | sharing of electrons |
| D. | transfer of electrons |
| Answer» E. | |
| 171. |
Crystal structure of a material can be studied by: |
| A. | Electron microscopy |
| B. | X-ray diffraction |
| C. | Neutron-diffraction |
| D. | All of the above |
| Answer» C. Neutron-diffraction | |
| 172. |
Thermoplastic and thermoset polymers differ in: |
| A. | Glass transition temperature |
| B. | Thermal behaviour |
| C. | Mechanical behaviour |
| D. | All of the above |
| Answer» C. Mechanical behaviour | |
| 173. |
An example of piezoelectric material is: |
| A. | Corundum |
| B. | Quartz |
| C. | BaTiO |
| D. | <sub>3</sub> |
| E. | All of these |
| Answer» C. BaTiO | |
| 174. |
The permeability and permittivity of a medium are: |
| A. | independent to each other |
| B. | related by the velocity of EM waves |
| C. | related by the Boltzman constant |
| D. | All of the above |
| Answer» C. related by the Boltzman constant | |
| 175. |
Consider the following statements: Superconductivity in a material can be destroyed by |
| A. | 2, 3 and 4 |
| B. | 1, 3 and 4 |
| C. | 1, 2 and 3 |
| D. | 1, 2 and 4 |
| Answer» E. | |
| 176. |
The following figure gives the schematic arrangement of spins of four different types of magnetic materials: |
| A. | I and II respectively |
| B. | II and III respectively |
| C. | I and III respectively |
| D. | II and IV respectively |
| Answer» E. | |
| 177. |
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. | |
| 178. |
Superconductivity can be destroyed by: |
| A. | application of magnetic field |
| B. | reducing temperatures |
| C. | adding impurities |
| D. | none of the above |
| Answer» B. reducing temperatures | |
| 179. |
Which of the following has the highest resistivity? |
| A. | Mineral oil |
| B. | Paraffin wax |
| C. | Air |
| D. | Mica |
| Answer» D. Mica | |
| 180. |
The conductivity of a metal at ultraviolet frequency (10 |
| A. | infinity |
| B. | zero |
| C. | dc conductivity |
| D. | half of dc conductivity |
| Answer» B. zero | |
| 181. |
If the molecular structure and density of the material are known, then which of the following material parameters may be determined from the |
| A. | Sum of electronic and ionic polarizabilities |
| B. | Lattice constant |
| C. | Breakdown voltage |
| D. | Loss tangent |
| Answer» B. Lattice constant | |
| 182. |
Consider a single crystal of an intrinsic semiconductor. The number of free carriers at the Fermi level at room temperature is: |
| A. | half the total number of electrons in the crystal |
| B. | half the number of free electrons in the crystal |
| C. | half the number of atoms in the crystal |
| D. | zero |
| Answer» C. half the number of atoms in the crystal | |
| 183. |
High frequency amplifier use transformers with : |
| A. | alnico core |
| B. | ferrite core |
| C. | iron core |
| D. | none of these |
| Answer» C. iron core | |
| 184. |
Audio and power amplifiers use transformers with: |
| A. | Laminated iron core |
| B. | Solid iron core |
| C. | Ferrite core |
| D. | None of these |
| Answer» B. Solid iron core | |
| 185. |
Transistors (with transfer resistance characteristics) were discovered by: |
| A. | W. Schockley |
| B. | Bardeen and Brattain |
| C. | Siemen |
| D. | All of the above |
| Answer» B. Bardeen and Brattain | |
| 186. |
Orientational polarization is: |
| A. | inversely proportional to temperature and proportional to the square of the permanent dipole moment |
| B. | proportional to temperature as well as to the square of the permanent dipole moment |
| C. | proportional to temperature and inversely proportional to the square of the permanent dipole moment |
| D. | inversely proportional to temperature as well as to the square of dipole moment. |
| Answer» B. proportional to temperature as well as to the square of the permanent dipole moment | |
| 187. |
Above the Curie temperature, the hysteresis loop of a ferroelectric material can be described by a: |
| A. | parabola |
| B. | cycloid |
| C. | straight line |
| D. | point |
| Answer» C. straight line | |
| 188. |
Which of the following crystallographic defects contribute to electronic defects? |
| A. | 1, 2 and 3 |
| B. | 2, 3 and 4 |
| C. | 1, 3 and 4 |
| D. | 1, 2 and 4 |
| Answer» C. 1, 3 and 4 | |
| 189. |
Some of the characterizing parameters of a material are: |
| A. | 1 and 3 |
| B. | 3 and 2 |
| C. | 4 and 3 |
| D. | 1 and 2 |
| Answer» C. 4 and 3 | |
| 190. |
Some of the electrons are injected into the interior of a conductor surrounded by an insulator. The injected electrons will: |
| A. | distribute themselves uniformly |
| B. | distribute themselves randomly |
| C. | be confined at the point of injection |
| D. | travel to the surface of the conductor |
| Answer» E. | |
| 191. |
The Hall effect voltage in intrinsic silicon: |
| A. | is positive |
| B. | is zero |
| C. | is negative |
| D. | changes sign on application of magnetic field |
| Answer» D. changes sign on application of magnetic field | |
| 192. |
Three B-H curves are shown in the figure. The curves X, Y and Z refer respectively to: |
| A. | diamagnet, paramagnet and ferromagnet |
| B. | paramagnet, ferromagnet and diamagnet |
| C. | ferromagnet, diamagnet and paramagnet |
| D. | Ferromagnet, paramagnet and diamagnet |
| Answer» E. | |
| 193. |
In a piezoelectric crystal oscillator, the oscillation or turning frequency is linearly proportional to the: |
| A. | mass of the crystal |
| B. | square root of the mass of the crystal |
| C. | square of the mass of the crystal |
| D. | inverse of the square root of the mass of the crystal |
| Answer» E. | |
| 194. |
Constantan is an alloy composed of: |
| A. | 86% copper, 12% manganese and 2% nickel |
| B. | 76% nickel, 21% chromium, 2% manganese and 1% iron |
| C. | 60% copper and 40% nickel |
| D. | 40% copper, 40% nickel and 20% carbon |
| Answer» D. 40% copper, 40% nickel and 20% carbon | |
| 195. |
The coercive force in a ferromagnetic material is related to the: |
| A. | area enclosed by the B H loop |
| B. | intercept on the negative H-axis of the B H loop |
| C. | intercept on the positive B-axis of the B H loop |
| D. | maximum value of B on the B H loop |
| Answer» C. intercept on the positive B-axis of the B H loop | |
| 196. |
Consider the following statements: In the case of diamagnetic materials, the magnetic susceptibility is : |
| A. | 1 and 3 are correct |
| B. | 2 and 3 are correct |
| C. | 1 and 4 are correct |
| D. | 2 and 4 are correct |
| Answer» C. 1 and 4 are correct | |
| 197. |
Which of the following insulators are used for high frequency applications? |
| A. | Forsterite |
| B. | Bakelite |
| C. | Steatite |
| D. | All of these |
| Answer» B. Bakelite | |
| 198. |
Bragg s equation for X-ray diffraction from crystal planes is given by: |
| A. | |
| B. | <table><tr><td rowspan="2">d =</td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>n </center></td><td rowspan="2">sin </td></tr><tr><td style="text-align: center;">2</td></tr></table> |
| C. | n = 2d sin |
| D. | <table><tr><td rowspan="2"> =</td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center>2dn</center></td></tr><tr><td style="text-align: center;">sin </td></tr></table> |
| E. | All of these |
| Answer» C. n = 2d sin | |
| 199. |
In a certain temperature range, the electrical conductivity of a semiconductor increases with increase in temperature. This is because: |
| A. | both carrier concentration and mobility of carriers increase with increasing temperature |
| B. | both carrier concentration and mobility of carriers decrease with increasing temperature |
| C. | the carrier concentration increases substantially, but the mobility of carriers decreases with increase in temperature |
| D. | the carrier concentration remains constant but the mobility of carriers increases in temperature |
| Answer» D. the carrier concentration remains constant but the mobility of carriers increases in temperature | |
| 200. |
As compared to metals, modulus of elasticity of plastics is usually: |
| A. | lesser |
| B. | greater |
| C. | almost equal |
| D. | All of these |
| Answer» B. greater | |