Electrical Engineering Materials Mcqs – (Electrical Engineering) MCQs Latest For FPSC, PPSC, NTS, KPPSC, SPSC & Other Tests
“ Electrical Engineering Materials Mcqs“. Tab this page to check “Latest Electrical Engineering Materials Mcqs “ for the preparation of competitive mcqs, FPSC mcqs, PPSC mcqs, SPSC mcqs, KPPSC mcqs, AJKPSC mcqs, BPSC mcqs, NTS mcqs, PTS mcqs, OTS mcqs, Atomic Energy mcqs, Pak Army mcqs, Pak Navy mcqs, CTS mcqs, ETEA mcqs and others. The most occurred mcqs of Electrical Engineering Materials in past papers. Past papers of Electrical Engineering Materials Mcqs. Past papers of Electrical Engineering Materials Mcqs. Mcqs are the necessary part of any competitive / job related exams. The Electrical Engineering Materials Mcqs having specific numbers in any written test. It is therefore everyone have to learn / remember the related Electrical Engineering Materials Mcqs. The Important series of Electrical Engineering Materials Mcqs are given below:
The covalent bond is formed by_______________?
A. sharing of variable number of electrons by a variable number of atoms
B. sharing of electrons between atoms
E. transfer of electrons between atoms
D. none of the above
The tiny block formed by the arrangement of a small group of atoms is called the____________?
A. unit cell
B. space lattice
C. either of the above
D. none of the above
is a negatively charged particle present in an atom______________?
A. Neutron
B. Proton
C. Electron
D. None of the above
The converse of hardness is known as______________?
A. toughness
B. malleability
C. softness
D. none of the above
The formula __________ determines the number of electrons that can be accommodated in any level?
A. 2n2
B. 2n3
C. 4n2
D. 4ns
A perfect conductor has_____________?
A. unity conductivity
B. zero conductivity
C. infinite conductivity
D. none of the above
Commonly used conducting materials are_____________?
A. aluminium
B. copper
C. both (A) and (B)
D. copper and silver
E. platinum and gold
The kinetic energy of a bounded electron is______________?
A. less than that of unbounded electron
B. equal to that of unbounded electron
C. greater than that of unbounded electron
D. infinite
E. none of the above
The metal having the lowest temperature coefficient of resistance is_________________?
A. gold
B. aluminium
C. copper
D. kanthal
The co-ordination number of a simple cubic structure is______________?
A. 4
B. 2
C. 6
D. 8
A highly conductive material must have___________?
A. good mechanical strength
B. lowest temperature co-efficient
C. highest conductivity
D. good corrosion resistance
E. easy solderable and drawable quality
F. all of the above
Which of the following materials is preferred for transmitting electrical energy over long distance ?
A. Aluminium
B. Copper
C. Steel reinforced copper
D. Steel reinforced aluminium
Superconductors are becoming popular for use in________________?
A. generating very strong magnetic field
B. generating electrostatic field
C. manufacture of bubble memories
D. generating regions free from magnetic field
The superconductivity is due to____________?
A. the crystal structure having no atomic vibration at 0°K
B. the electrons jump into nucleus at 0°K
C. all electrons interact in the super-conducting state
D. none of the above
The conductivity of a conductor can be increased by_______________?
A. decreasing its temperature
B. decreasing its vibration
C. increasing its temperature
D. increasing its vibration
In a superconductor the value of critical density depends upon______________?
A. temperature
B. magnetic field strength
C. either (A) or (B)
D. both (A) and (B)
High resistivity materials are used in_____________?
A. heating elements
B. precision instruments
C. motor starters
D. incandescent lamps
E. all of the above
highest conductivity_____________?
B. good mechanical strength
C. lowest temperature co-efficient
D. good corrosion resistance
E. easy solderable and drawable quality
F. all of the above
Superconductivity is observed for____________?
A. a.c. and high frequency
B. d.c. and low frequency
C. infrared frequencies
D. frequencies having no effect
E. none of the above
The value of critical field below the transition temperature will_______________?
A. increase
B. remain unchanged
C. decrease
D. any of the above
On which of the following factors does the resistivity of a material depend ?
A. Area of the conductor section
B. Resistance of the conductor
C. Length of the conductor
D. All of the above
Mercury as an electric contact material is_______________?
A. a metal
B. a liquid
C. a metal liquid
D. a gas
Which of the following resistive materials has the lowest temperature co-efficient of resistance ?
A. Nichrome
B. Kanthal
C. Constantan
D. Molybdenum
The conductors have transport phenomena of electrons due to____________?
A. electric field
B. electromagnetic field
C. magnetic field
D. none of the above
An H.R.C. fuse is_______________?
A. a ceramic body having metal and caps
B. a heavy cross-section of copper or aluminium
C. a wire of platinum
D. a ceramic tube having carbon rod inside it
The coils of D.C. motor starter are wound with wire of_______________?
A. kanthal
B. copper
C. manganin
D. nichrome
By increasing impurity content in the metal alloy the residual resistivity always_____________?
A. remains constant
B. increases
C. decreases
D. becomes temperature independent
At transition temperature the value of critical field is____________?
A. zero
B. positive real value
C. negative real value
D. complex value
The transition temperature of mercury is____________?
A. 9.22°K
B. 18.0°K
C. 4.12°K
D. 1.14’K
The structure sensitive property of a super conductor is______________?
A. transition temperature
B. critical magnetic field
C. critical current density
D. none of the above
Constantan contains_______________?
A. copper and tungsten
B. silver and tin
C. tungsten and silver
D. copper and nickel
Which of the following is the poorest conductor of electricity ?
A. Carbon
B. Silver
C. Steel
D. Aluminium
Which of the following variety of copper has the best conductivity ?
A. Hard drawn copper
B. Induction hardened copper
C. Pure annealed copper
D. Copper containing traces of silicon
Overhead telephone wires are made of_____________?
A. ACSR conductors
B. steel
C. aluminium
D. copper
__________ is the main constituent of glass?
A. AI2O3
B. Si02
C. Fe203
D. B2O3
___________ is most commonly used for making magnetic recording tape?
A. Small particles of iron
B. Ferric oxide
C. Silver nitrate
D. Silicon-iron
Carbon electrodes are not used in_______________?
A. GLS lamps
B. dry cells
C. electric arc furnace
D. cinema projectors
In thermocouples which of the following pairs is commonly used ?
A. Copper-constantan
B. Silver-German silver
C. Aluminium-tin
D. Iron-steel
Solder is an alloy of______________?
A. nickel, copper and zinc
B. tin and lead
C. copper and aluminium
D. silver, copper and lead
_____________is viscoelastic?
A. Graphite
B. Cast-iron
C. Rubber
D. Glass
Piezoelectric materials serve as a source of ____________ ?
A. musical waves
B. resonant waves
C. microwaves
D. ultrasonic waves
_________ is an example of piezoelectric material?
A. Corrundum
B. Quartz
C. Glass
D. Neoprene
A good electric contact material should have all of the following properties except_____________?
A. high resistivity
B. good thermal conductivity
C. high resistance to corrosion
D. high melting point
Thermonic emission occurs in______________?
A. vacuum tubes
B. ferrite cores
C. copper conductors
D. transistors
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
Most of the common metals have _________ structure?
A. hexagonal
B. linear
C. orthorhombic
D. cubic
__________ is a hard solder?
A. Tin-silver-lead
B. Tin-lead
C. Copper-zinc
D. None of the above
Which of the following affect greatly the resistivity of electrical conductors ?
A. Composition
B. Size
C. Pressure
D. Temperature
Super conductivity can be destroyed by_____________?
A. reducing temperatures
B. adding impurities
C. application of magnetic field
D. any of the above
Which of the following materials does not have covalent bonds ?
A. Silicon
B. Organic polymers
C. Metals
Non-linear resistors______________?
A. produce harmonic distortion
B. result in non-uniform heating
C. follows Ohm’s law at low temperatures only
D. none of the above
In graphite, bonding is____________?
A. metallic
B. covalent
C. Vander Waals
D. Vander Waals and covalent
A carbon resistor contains_____________?
A. solid carbon granules
B. carbon crystals
C. pulverized coal
D. finely divided carbon black
Total number of crystal systems is____________?
A. 4
B. 2
C. 7
D. 12
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 gas density varies with temperature
C. the electron density varies with temperature
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
D. Any of the above
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 of the above
D. none of the above
In a crystal, an atom vibrates at a frequency determined by_______________?
A. the temperature of the crystal
B. the heat content of the crystal
C. the stiffness of the bonds it makes with neighbors
The number of atoms per unit cell in B.C.C. structure is_____________?
A. 4
B. 2
C. 1
D. 8
Which of the following material is not a semiconductor ?
A. Silica
B. Selenium
C. Germanium
D. Gallium-arsenide
Carbon rods are used in wet and dry cells because_____________?
A. carbon can resist the attack of battery acid
B. carbon rod serves as conductor
C. both (A) and (B)
D. either (A) or (B)
Which of the following are non-conductors of electricity?
A. Air and most other gases
B. Non-metal solids except carbon
C. Pure water and liquids in general except mercury
D. All of the above
Carbon resistors are used extensively because they are____________?
A. compact
B. easy to make
C. inexpensive
D. all of the above reasons
The impurity atoms is semiconductors_____________?
A. increase the kinetic energy of valence electrons
B. reduce the energy gap
C. inject more charge carriers
D. all of the above
Due to which of the following factors the brush wear rate is altered ?
A. Contact pressure
B. Speed of the machine
C. Surface conditions of brush and commutator
D. Excessive sparking
E. All of the above
Carbon bearings are used under which of the following conditions ?
A. Where corrosive chemical action exists
B. Where lubrication is difficult or im-possible
C. Where high temperature exists
D. All of the above
Steel wire is used as____________?
A. earth wire
B. overhead telephone wire
C. core wire of ACSR
D. all of the above
Platinum is used in_____________?
A. thermocouple
B. electrical contacts
C. heating element in high temperature furnace
D. grids of special purpose vacuum tubes
E. all of the above
Which of the following high resistance materials has the highest operating temperature ?
A. Kanthal
B. Nichrome
C. Manganin
D. Eureka
Low resistivity materials are used in__________?
A. transmission and distribution lines
B. transformer, motor and generator windings
C. house wiring
D. all above applications
Which of the following materials is used for making coils of standard resistances ?
A. Nichrome
B. Copper
C. Platinum
D. Manganin
Copper, even though costly, finds use in the windings of electrical machines because_____________?
A. copper can be easily soldered and welded
B. copper points offer low contact resistance
E. copper windings are less bulky and the machines become compact
D. all of the above
Which of the following is an advantage of stranded conductor over equivalent single conductor ?
A. Greater flexibility
B. Less liability to kink
C. Less liability to break
D. All of the above
Substances whose specific resistance abruptly decreases at very low temperature are called___________?
A. conductors
B. insulators
C. semiconductors
D. superconductors
is the property of absorbing moisture from atmosphere_____________?
A. Viscosity
B. Solubility
C. Porosity
D. Hygroscopicity
The conduction of electricity, in semiconductors, takes place due to movement of______________?
A. negative ions only
B. positive ions only
C. positive and negative ions
D. electrons and holes
Thermocouples are mainly used for the measurement of_____________?
A. temperature
B. eddy currents
C. resistance
D. coupling co-efficient
Which of the following materials is the best conductor of electricity ?
A. Aluminium
B. Tungsten
C. Copper
D. Carbon
Due to which of the following reasons copper and aluminium are not used for heating elements ?
A. Both have great tendency for oxidation
B. Very large length of wires will be required
C. Both have low melting point
D. All of the above
Which of the following is a semiconductor material ?
A. Rubber
B. Phosphorous
C. Silicon
D. Aluminium
___________ has the best damping properties?
A. High speed steel
B. Diamond
C. Mild steel
D. Cast iron
Spark plug makes use of which of the following materials for insulation ?
A. Porcelain
B. Asbestos
C. Slate
D. Glass
The photo-electric effect occurs only when the incident light has more than a certain critical____________?
A. speed
B. intensity
C. frequency
D. wave length
Selenium is __________ semiconductor?
A. N-type
B. intmisic
C. extrnisic
D. P-type
Due to which of the following fact, in India, aluminium is replacing copper ?
A. Aluminium has lower resistivity than that of copper
B. Aluminium is available in plenty, cheaper and lighter than copper
C. Aluminium is more ductile and malleable than copper
D. Aluminium has less temperature co-efficient than copper
If the resistance of a conductor does not vary in accordance with Ohm’s law it is known as____________?
A. non-linear conductor
B. bad-conductor
C. reverse conductor
D. non-conductor
The forbidden gap in an insulator is________________?
A. large
B. nil
C. small
D. any of the above
Effect of moisture on the insulating materials is to________________?
A. decrease dielectric strength
B. decrease dielectric constant
C. decrease insulation resistance
D. increase dielectric loss
E. all of the above
In conductors conduction of electricity takes place due to movement of_______________?
A. electrons only
B. negative ions only
C. positive ions only
D. positive and negative ions
E. none of the above
Surface resistance of an insulating material is reduced due to the______________?
A. humidity in the atmosphere
B. smoky and dirty atmosphere
C. both (A) and (b)
D. neither (A) nor (b)
Which of the following factors affect resistivity of metals ?
A. Alloying
B. Age hardening
C. Temperature
D. Cold work
E. All of the above
Superconducting metal in super conducting state has relative permeability of________________?
A. zero
B. negative
C. one
D. more than one
For a particular material the Hall coefficient was found to be zero. The material is______________?
A. intrinsic semiconductor
B. metal
C. insulator
D. none of the above
For a hole which of the following statements is incorrect ?
A. Holes may constitute an electric current
B. Holes can exist in any material including conductors
C. Holes can exist in certain semiconductors only
D. Holes can be considered as a net positive charge
The conductivity of an extrinsic semiconductor with temperature________________?
A. increases
B. decreases
C. remains constant
The carbon percentage is least in__________________?
A. cast iron
B. wrought iron
C. low carbon steel
D. malleable iron
is an element used in semiconductors whose atoms have three valence electrons?
A. An acceptor
B. Germanium
C. A donor
D. Silicon
For germanium the forbidden energy gap is_______________?
A. 0.25 eV
B. 0.15 eV
C. 0.5eV
D. 0.7eV
The current due to electron flow in conduction band is the hole current in valence band?
A. less than
B. equal to
C. greater than
D. any of the above
The minority carrier concentration is largely a function of_____________?
A. reverse biasing voltage
B. forward biasing voltage
C. temperature
D. the amount of doping