Which of the substances listed can be used to shield sensitive equipment from static magnetic fields? A. Glass B. Mica C. Bakelite D. Permeable iron

Which of the substances listed can be used to shield sensitive equipment from static magnetic fields? A. Glass B. Mica C. Bakelite D. Permeable iron
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Answer: D
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When placed in a magnetic field, which of the materials listed will maintain the highest permeability? A. Glass B. Bakelite C. Soft iron D. Aluminum

Description : When placed in a magnetic field, which of the materials listed will maintain the highest permeability? A. Glass B. Bakelite C. Soft iron D. Aluminum

Last Answer : Answer: C

Which of the listed pairs of materials make the best insulators? A. copper and aluminum B. glass and mica C. dry air and a vacuum D. doped silicon and germanium

Description : Which of the listed pairs of materials make the best insulators? A. copper and aluminum B. glass and mica C. dry air and a vacuum D. doped silicon and germanium

Last Answer : Answer: B

Which of the listed groups of electrical insulation materials is best suited for the highest operating temperatures? A. impregnated cotton and silk B. unimpregnated paper and cotton C. pure glass and quartz D. mica and porcelain with bonding agents

Description : Which of the listed groups of electrical insulation materials is best suited for the highest operating temperatures? A. impregnated cotton and silk B. unimpregnated paper and cotton C. pure glass and quartz D. mica and porcelain with bonding agents

Last Answer : Answer: C

A direct current passing through a wire coiled around a soft iron core is the description of a simple ____________. A. magnetic shield B. electromagnet C. piezoelectric device D. electromagnetic domain

Description : A direct current passing through a wire coiled around a soft iron core is the description of a simple ____________. A. magnetic shield B. electromagnet C. piezoelectric device D. electromagnetic domain

Last Answer : Answer: B

Which of the listed conditions might contribute to very rapid wearing of a DC machine's commutator bars? A. A grounded commutator bar B. Using improper carbon brushes C. Aligning the front and rear mica V-rings improperly D. An open circuit in the armature

Description : Which of the listed conditions might contribute to very rapid wearing of a DC machine's commutator bars? A. A grounded commutator bar B. Using improper carbon brushes C. Aligning the front and rear mica V-rings improperly D. An open circuit in the armature

Last Answer : Answer: B

Which of the listed faults cannot be eliminated, EXCEPT by turning or grinding a commutator with a rigidly supported tool? A. Sparking brushes B. Eccentricity C. High mica D. Blackened commutator

Description : Which of the listed faults cannot be eliminated, EXCEPT by turning or grinding a commutator with a rigidly supported tool? A. Sparking brushes B. Eccentricity C. High mica D. Blackened commutator

Last Answer : Answer: B

In replacing a defective transformer with a new one, which of the following actions must be carried out to insure proper operation of the equipment it serves? A. The secondary leads must be grounded for 10 minutes to remove static charges. B. The transformer connections must be made as before with regard to the indicated polarity. C. The iron core of the transformer must be flashed to pre-magnetize it. D. The iron core must be grounded for 10 minutes to remove any residual magnetism.

Description : In replacing a defective transformer with a new one, which of the following actions must be carried out to insure proper operation of the equipment it serves? A. The secondary leads must be grounded ... magnetize it. D. The iron core must be grounded for 10 minutes to remove any residual magnetism.

Last Answer : Answer: B

One method of testing for a reversed shunt field coil in a DC generator or motor is by connecting the field to a direct current source, at reduced field rated voltage, and test for polarity using a/an ____________. A. iron bar across each field B. magnetic compass placed near each field C. test lamp across adjacent fields D. copper jumper across the interpole connections

Description : One method of testing for a reversed shunt field coil in a DC generator or motor is by connecting the field to a direct current source, at reduced field rated voltage, and test for ... placed near each field C. test lamp across adjacent fields D. copper jumper across the interpole connections

Last Answer : Answer: B

The electric and magnetic fields vary with time in which of the following fields? a) DC b) AC c) Static d) It does not vary with time

Description : The electric and magnetic fields vary with time in which of the following fields? a) DC b) AC c) Static d) It does not vary with time

Last Answer : b) AC

Which of the methods listed is used to maintain the division of load between two compound-wound, DC generators operating in parallel? A. The shunt fields are interconnected. B. The shunt field rheostats are interconnected. C. The series fields of both generators are connected in series. D. The equalizer connection parallels the series fields of all machines.

Description : Which of the methods listed is used to maintain the division of load between two compound-wound, DC generators operating in parallel? A. The shunt fields are interconnected. B. The shunt ... generators are connected in series. D. The equalizer connection parallels the series fields of all machines.

Last Answer : Answer: D

Which of the methods listed is used to maintain equal load sharing between two compound wound DC generators operating in parallel? A. The shunt fields are interconnected. B. The shunt field rheostats are interconnected. C. The series fields of both generators are connected in series. D. The series fields of both generators are connected in parallel.

Description : Which of the methods listed is used to maintain equal load sharing between two compound wound DC generators operating in parallel? A. The shunt fields are interconnected. B. The shunt field rheostats ... are connected in series. D. The series fields of both generators are connected in parallel.

Last Answer : Answer: D

The 'dielectric constant' is a numerical value indicating the effectiveness of a dielectric material in comparison to that of a standard, which is _______________. A. paper or cloth B. glass or mica C. plastic or Teflon D. dry air or a vacuum

Description : The 'dielectric constant' is a numerical value indicating the effectiveness of a dielectric material in comparison to that of a standard, which is _______________. A. paper or cloth B. glass or mica C. plastic or Teflon D. dry air or a vacuum

Last Answer : Answer: D

In which of the following industries is mica used as a raw material? (a) Electrical (b) Iron and steel (c) Toys (d) Glass and pottery

Description : In which of the following industries is mica used as a raw material? (a) Electrical (b) Iron and steel (c) Toys (d) Glass and pottery

Last Answer : Ans:(a)

Which is an amorphous material? (A) Glass (B) Mica (C) Brass (D) Cast iron

Description : Which is an amorphous material? (A) Glass (B) Mica (C) Brass (D) Cast iron

Last Answer : (A) Glass

Cell membranes a. consist almost entirely of protein molecules b. are impermeable to fat-soluble substances c. in some tissues permit the transport of glucose at a greater rate in the presence of insulin d. are freely permeable to electrolytes but not to proteins e. have a stable composition throughout the life of the cell

Description : Cell membranes a. consist almost entirely of protein molecules b. are impermeable to fat-soluble substances c. in some tissues permit the transport of glucose at a greater rate in the presence of ... to electrolytes but not to proteins e. have a stable composition throughout the life of the cell

Last Answer : in some tissues permit the transport of glucose at a greater rate in the presence of insulin

Which of the substances listed should be applied to battery terminals to help prevent corrosion? A. Zinc chromate B. Naval jelly C. Lead peroxide D. Petroleum jelly

Description : Which of the substances listed should be applied to battery terminals to help prevent corrosion? A. Zinc chromate B. Naval jelly C. Lead peroxide D. Petroleum jelly

Last Answer : Answer: D

In which of the situations listed will a megohmmeter give the most accurate readings? A. While the machine is in operation. B. While the machine is discharging static electricity. C. Immediately prior to restarting the machine. D. When the machine has been shut down and grounded for a period of 15 minutes.

Description : In which of the situations listed will a megohmmeter give the most accurate readings? A. While the machine is in operation. B. While the machine is discharging static electricity. C. Immediately prior to ... machine. D. When the machine has been shut down and grounded for a period of 15 minutes.

Last Answer : Answer: D

What is used to wash oily substances from glass equipment in laboratory ?

Description : What is used to wash oily substances from glass equipment in laboratory ?

Last Answer : There are many compounds that can remove oil. Such as: sodium carbonate solution , Deacon-90 , chromic acid mixture. However chromic acid mixture is the best cleaner.

Which of the spaces listed is defined as a 'location requiring an exceptional degree of protection' when considering the installation of shipboard electrical equipment? A. Machinery space B. Chart room C. Console room D. Accommodation space

Description : Which of the spaces listed is defined as a 'location requiring an exceptional degree of protection' when considering the installation of shipboard electrical equipment? A. Machinery space B. Chart room C. Console room D. Accommodation space

Last Answer : Answer: A

When working on electrical circuits containing large capacitors, in addition to deenergizing the circuit, which of the listed precautions should also be taken? A. Keep all radio equipment away. B. Measure capacitor insulation resistance. C. Ground the capacitor terminals. D. Check capacitor circuit polarity.

Description : When working on electrical circuits containing large capacitors, in addition to deenergizing the circuit, which of the listed precautions should also be taken? A. Keep all radio equipment ... capacitor insulation resistance. C. Ground the capacitor terminals. D. Check capacitor circuit polarity.

Last Answer : Answer: C

An insulation resistance test is performed on a particular piece of electric equipment. In addition to the resistance reading, what information listed below should be entered in the electrical log? A. The maximum allowable operating temperature of the machine. B. The temperature of the machine at the time the resistance reading was taken. C. The normal temperature rise of the machine. D. The complete nameplate data from the resistance test instrument used to obtain the reading.

Description : An insulation resistance test is performed on a particular piece of electric equipment. In addition to the resistance reading, what information listed below should be entered in the electrical log? A. ... D. The complete nameplate data from the resistance test instrument used to obtain the reading.

Last Answer : Answer: B

Which of the listed procedures should be carried out to prevent moisture damage to electrical apparatus during extended periods of idleness? A. Fill the motor housing with CO2 to inert the space. B. Strap silica gel around the commutator. C. Place heat lamps in the motor housings. D. Cover the equipment with a canvas tarpaulin.

Description : Which of the listed procedures should be carried out to prevent moisture damage to electrical apparatus during extended periods of idleness? A. Fill the motor housing with CO2 to inert the space. B. Strap ... C. Place heat lamps in the motor housings. D. Cover the equipment with a canvas tarpaulin.

Last Answer : Answer: C

Low voltage releases as used in some shipboard motor starter and control equipment will have which of the following characteristics? A. They trip circuit contactors when the motor starts to overspeed. B. They require manual resetting upon restoration of normal voltage. C. They use a phase sensitive relay to trip contacts in series with the holding coil of the starter. D. They allow the motor to restart upon restoration of normal voltage.

Description : Low voltage releases as used in some shipboard motor starter and control equipment will have which of the following characteristics? A. They trip circuit contactors when the motor starts to overspeed. B. ... coil of the starter. D. They allow the motor to restart upon restoration of normal voltage.

Last Answer : Answer: D

The purpose of an impressed current cathodic protection system aboard ship is to _______________. A. prevent corrosion of the hull, propeller, rudder and line shafting B. neutralize the vessel's stray magnetic fields which would interfere with radar C. protect engine room and deck machinery from oxidation in the presence of salt air D. maintain a minimum constant alternator load to prevent overheating

Description : The purpose of an impressed current cathodic protection system aboard ship is to _______________. A. prevent corrosion of the hull, propeller, rudder and line shafting B. neutralize the vessel's ... the presence of salt air D. maintain a minimum constant alternator load to prevent overheating

Last Answer : Answer: A

The relative speed between the magnetic fields of stator and rotor under steady state operation is zero for a (A) dc machine. (B) 3 phase induction machine. (C) synchronous machine. (D) single phase induction machine.

Description : The relative speed between the magnetic fields of stator and rotor under steady state operation is zero for a (A) dc machine. (B) 3 phase induction machine. (C) synchronous machine. (D) single phase induction machine.

Last Answer : Ans: all options are correct

A permeable substance is one (a) which is a good conductor (6) which is a bad conductor (c) which is a strong magnet (d) through which the magnetic lines of force can pass very easily

Description : A permeable substance is one (a) which is a good conductor (6) which is a bad conductor (c) which is a strong magnet (d) through which the magnetic lines of force can pass very easily

Last Answer : (d) through which the magnetic lines of force can pass very easily

Which of the listed electrical devices is represented by the symbol shown in the illustration? EL-0055 A. Fixed resistance resistor B. Coil with magnetic core C. DC motor or generator shunt field D. Transformer

Description : Which of the listed electrical devices is represented by the symbol shown in the illustration? EL-0055 A. Fixed resistance resistor B. Coil with magnetic core C. DC motor or generator shunt field D. Transformer

Last Answer : Answer: D

The schematic diagram shown in the illustration represents which of the listed solid-state circuits? EL-0069 A. Bridge rectifier B. Magnetic amplifier C. Flip-flop generator D. Cathodic amplifier

Description : The schematic diagram shown in the illustration represents which of the listed solid-state circuits? EL-0069 A. Bridge rectifier B. Magnetic amplifier C. Flip-flop generator D. Cathodic amplifier

Last Answer : Answer: A

A three-phase, induction-type motor experiences an open in one phase. Which of the listed automatic protective devices will prevent the machine from being damaged? A. Overspeed trip B. Thermal overload relay C. Three-pole safety switch D. Magnetic blowout coil

Description : A three-phase, induction-type motor experiences an open in one phase. Which of the listed automatic protective devices will prevent the machine from being damaged? A. Overspeed trip B. Thermal overload relay C. Three-pole safety switch D. Magnetic blowout coil

Last Answer : Answer: B

The working of a meter is based on the use of a permanent magnet. In order to protect the meter functioning from stray magnetic fields (a) meter is surrounded by strong magnetic fields (b) a soft iron shielding is used (c) a plastic shielding is provided (d) a shielding of anon-magnetic material is used

Description : The working of a meter is based on the use of a permanent magnet. In order to protect the meter functioning from stray magnetic fields (a) meter is surrounded by strong magnetic fields (b) a soft ... is used (c) a plastic shielding is provided (d) a shielding of anon-magnetic material is used

Last Answer : (b) a soft iron shielding is used

Bakelite (phenol-formaldehyde) resin cannot be used as (A) Decorative paint (B) Decorative laminates (C) Electrical insulation (D) Glass reinforced plastics

Description : Bakelite (phenol-formaldehyde) resin cannot be used as (A) Decorative paint (B) Decorative laminates (C) Electrical insulation (D) Glass reinforced plastics

Last Answer : (A) Decorative paint

The chlorinator used in the manufacture of DDT is made of(A) Glass(B) Glass lined steel(C) Teflon(D) Bakelite

Description : The chlorinator used in the manufacture of DDT is made of (A) Glass (B) Glass lined steel (C) Teflon (D) Bakelite

Last Answer : (B) Glass lined steel

Which glass is used as the wind shield of the motor cars?

Description : Which glass is used as the wind shield of the motor cars?

Last Answer : Safety glass (laminated glass)

……cables are composed of a glass or plastic inner core surrounded by cladding,all encased in an outside jacket. a. Fiber-optic b. Coaxial c. Shield Twisted Pair d. Unshield Twisted-pair

Description : ……cables are composed of a glass or plastic inner core surrounded by cladding,all encased in an outside jacket. a. Fiber-optic b. Coaxial c. Shield Twisted Pair d. Unshield Twisted-pair

Last Answer : a. Fiber-optic

Why are there no questions for me in the "questions for you" area when I have several interests and fields of expertise listed?

Description : Why are there no questions for me in the "questions for you" area when I have several interests and fields of expertise listed?

Last Answer : Broader categories work better If you want more questions. That and people have to ask and tag questions that are relevant to you for them to be for you.

Subschema can be used to A. create very different, personalized views of the samedata B. present information in different formats C. hide sensitive informationby omitting fields from thesub¬schema's description D. All of theabove E. None of the above

Description : Subschema can be used to A. create very different, personalized views of the samedata B. present information in different formats C. hide sensitive informationby omitting fields from thesub¬schema's description D. All of theabove E. None of the above

Last Answer : All of theabove

Magnets attract magnetic substances are iron, nickel, cobalt, etc. They can also repel - (1) paramagnetic substances (2) ferromagnetic substances (3) diamagnetic substances (4) non-magnetic substances

Description : Magnets attract magnetic substances are iron, nickel, cobalt, etc. They can also repel - (1) paramagnetic substances (2) ferromagnetic substances (3) diamagnetic substances (4) non-magnetic substances

Last Answer : (3) diamagnetic substances Explanation: Those materials which when placed in a magnetic field become weakly magnetized in a direction opposite to that of the applied field, are called as diamagnetic materials ... : bismuth, antimony, copper, gold, quartz, mercury, water, alcohol, air, hydrogen etc.

Which of the following comprises of hydrocarbons? (A) Mica flakes (B) Glass (C) Rubber (D) None of these

Description : Which of the following comprises of hydrocarbons? (A) Mica flakes (B) Glass (C) Rubber (D) None of these

Last Answer : (C) Rubber

Glass is made of the mixture of-------? A. Quartz and Mica B. Sand and Salt C. Sand and Silicates (Answer) D. None of these

Description : Glass is made of the mixture of-------? A. Quartz and Mica B. Sand and Salt C. Sand and Silicates (Answer) D. None of these

Last Answer : C. Sand and Silicates (Answer)

A material in which the atoms are arranged regularly in some directions but not in others, is termed as 'mesomorphous material'; an example of which is (A) Lead (B) Glass (C) Mica (D) Silver

Description : A material in which the atoms are arranged regularly in some directions but not in others, is termed as 'mesomorphous material'; an example of which is (A) Lead (B) Glass (C) Mica (D) Silver

Last Answer : (A) Lead

Which of the following is not a dielectric material? (A) Cotton, silk and paper (B) Asbestos, glass, porcelain and mica (C) Rubber and polymeric resins (D) All refractory materials

Description : Which of the following is not a dielectric material? (A) Cotton, silk and paper (B) Asbestos, glass, porcelain and mica (C) Rubber and polymeric resins (D) All refractory materials

Last Answer : Option C

Write one application for the give dielectric material. (i) Polyvinyl Carbide(PVC) (ii) Glass (iii) Mica (iv) Cotton and Silk

Description : Write one application for the give dielectric material. (i) Polyvinyl Carbide(PVC) (ii) Glass (iii) Mica (iv) Cotton and Silk

Last Answer : (i) Polyvinyl Carbide(PVC):it is used in insulation of wires and cables in domestic wiring as well as in aircraft and factory wiring (any one)  (ii) Glass: 1) Alkaline glasses are used for ... with wax or varnishes are used in windings of magnet coils and small medium sized mechanics (any one) 

The line integral of which parameter is zero for static fields? a) E b) H c) D d) B

Description : The line integral of which parameter is zero for static fields? a) E b) H c) D d) B

Last Answer : a) E

For static fields, the curl of E will be a) Rotational b) Irrotational c) Solenoidal d) Divergent

Description : For static fields, the curl of E will be a) Rotational b) Irrotational c) Solenoidal d) Divergent

Last Answer : b) Irrotational

Which of the following identities is always zero for static fields? a) Grad(Curl V) b) Curl(Div V) c) Div(Grad V) d) Curl(Grad V)

Description : Which of the following identities is always zero for static fields? a) Grad(Curl V) b) Curl(Div V) c) Div(Grad V) d) Curl(Grad V)

Last Answer : d) Curl(Grad V)

Mica is a (A) Dielectric material. (B) Insulating material. (C) Magnetic material. (D) Both insulating and dielectric material.

Description : Mica is a (A) Dielectric material. (B) Insulating material. (C) Magnetic material. (D) Both insulating and dielectric material.

Last Answer : (D) Both insulating and dielectric material.