Properties of Insulating Material

Properties of Insulating Material
by

1 Answer

Answer :

i. Thermal conductivity: Thermal conductivity of insulating material should be as possible to reduce the thickness of material. ii. Nonflammable: Insulating material should be fire proof and nonflammable for safety purpose. iii. Odour less: Insulating material should not possess its own odour and it should not pick the odour of other substance placed in refrigerated space. iv. Low Cost: It should be of low cost and should available easily. v. Strength vi. Chemical Stability. vii. Moisture Resistance.
by

Related questions

Desirable properties of refrigerant.

Description : Desirable properties of refrigerant.

Last Answer : a) Boiling point at atmospheric pressure should be low. b) Freezing point at atmospheric pressure should be low. c) Latent heat of vaporization of refrigerant must be high. d) Critical temperature ... k) It should have high thermal conductivity. l) It should have chemical stability.

Carnot cycle efficiency depends upon  (a) properties of the medium/substance used  (b) condition of engine  (c) working condition  (d) temperature range of operation  (e) effectiveness of insulating material around the engine.

Description : Carnot cycle efficiency depends upon  (a) properties of the medium/substance used  (b) condition of engine  (c) working condition  (d) temperature range of operation  (e) effectiveness of insulating material around the engine.

Last Answer : Answer : d

The insulating material for cables should (a) be acid proof (b) be non-inflammable (c) be non-hygroscopic (d) have all above properties

Description : The insulating material for cables should (a) be acid proof (b) be non-inflammable (c) be non-hygroscopic (d) have all above properties

Last Answer : (d) have all above properties

State various thermal insulating materials. State any two properties of insulating material

Description : State various thermal insulating materials. State any two properties of insulating material

Last Answer : Thermal insulating materials: 1) Asbestos 2) Aluminum Foil 3) Thermocol 4) Saw dust 5) Cork board slabs 6) Foam glass 7) Rock Wool 8) Glass Wool 9) ... . h) Presence of Moisture: with the increase in moisture content, the coefficient of thermal conductivity rises greatly

State two fundamental properties of insulating materials.

Description : State two fundamental properties of insulating materials.

Last Answer : Insulation resistance and dielectric strength.

What are the properties of sound insulating materials?

Description : What are the properties of sound insulating materials?

Last Answer : Properties of sound insulating materials: 1. It should be light in weight 2. Easy to handle and fix 3. It should be resistant to attack termite and insect 4. It should have low density and porous texture 5. It should be fire resistance 6. It should be moisture resistance

State the Properties of thermal insulating materials.

Description : State the Properties of thermal insulating materials.

Last Answer : Properties of thermal insulating materials: 1) Thermal insulating should be bio resistant and dry. 2) Thermal resistant should be chemically resistant and fire proof. 3) Thermal resisting ... in the moisture content in the material, the coefficient of thermal conductivity rises greatly.

State any two electrical, mechanical and thermal properties of insulating materials.

Description : State any two electrical, mechanical and thermal properties of insulating materials. 

Last Answer : i) Electrical Properties of insulating material:- 1. It should have high resistance. 2. It should have high breakdown voltage. 3. It should have high dielectric strength. 4. It should have low ... . 4. Ii should have thermal Stability. 5. Co-efficient of thermal expansion should be low.

State properties of insulating materials.

Description : State properties of insulating materials.

Last Answer : (i) Resistivity should be very high. (ii) It should be water resistant. (iii) It should not contain impurities. (iv) It should not be affected chemically and not corroded easily. (v) Its ... It should be mechanically strong (tensile strength should be more). (vii) It should not be porous.

Explain the mechanical properties of insulating materials.

Description : Explain the mechanical properties of insulating materials.

Last Answer : i) Mechanical strength: Mechanical strength depends on temperature and humidity. a) Temperature: High temperature badly affects the mechanical strength of insulating material. While selecting material ... material should have property of easy moulding and machined into required shape and size.

winter air conditioning

Description : winter air conditioning

Last Answer : In winter air conditioning, the air is heated which is generally followed by humidification. The schematic arrangement of the system is shown in Fig. The outside air flows through a damper ... loss of conditioned (or used) air through exhaust fans or ventilation from the conditioned space. 

Industrial application of refrigeration

Description : Industrial application of refrigeration

Last Answer : Air-conditioning for comfort of workers For textile industries for production of quality textile products. For manufacturing process in photographic industry. In printing industries ... devices test gauges and precision gears etc. where close tolerance of dimensions is required.

Working of domestic refrigerator

Description : Working of domestic refrigerator

Last Answer : Domestic Refrigerator : The internal parts of the refrigerator are ones that carry out actual working of the refrigerator. Some of the internal parts are located at the back of the refrigerator, and ... button or there is automatic system comprising of the electric heater and the timer.

Classify chiller and it application

Description : Classify chiller and it application

Last Answer : There are three different types of chillers: (1) air (2) water (3) evaporative condensed chiller Industrial chillers: (1) reciprocating, (2) centrifugal, (3) screw ... quality waste heat or cheap heat. They are often found in hospitals and buildings with heated swimming pools.

Working of evaporative type condenser

Description : Working of evaporative type condenser

Last Answer : Working of evaporative type condenser: Evaporative condensers combine the features of a cooling tower and water-cooled condenser in a single unit. In evaporative condensers, both air and water are used to extract ... The role of air is primarily to increase the rate of evaporation of water. 

Working of centrifugal compressor

Description : Working of centrifugal compressor 

Last Answer : Working of centrifugal compressor : When the air passes through the rotating impeller it experiences force or work which is performed by centrifugal forces. The work input takes place as an increase in ... about 65% and 35% of the total pressure developed or produced in the compressor.

Following factors are affecting on human comfort.

Description : Following factors are affecting on human comfort. 

Last Answer : 1. Temperature of air: In air conditioning, the control of temperature means the maintenance of any desired temperature within an enclosed space even though the temperature of the outside air is ... necessary that there should be equi-distribution of air throughout the space to be air conditioned. 

Dry compression

Description : Dry compression

Last Answer : Dry compression- Dry compression means completely dry vapour form of refrigerant enters the compressor before compression. In this removal of heat during evaporation process should be continued till the vapour gets ... lower for the entire system. so it's always preferred to go for dry compression. 

Vortex tube refrigeration

Description : Vortex tube refrigeration

Last Answer : Vortex tube refrigeration Working: - Vortex tube is simple device of producing cold. A compressed air is passed tangentially through nozzle. Here air velocity increases due to expansion and ... the diaphragm hole into the cold side, while hot stream is passed through the opening valve.

Hermetic sealed compressor

Description : Hermetic sealed compressor

Last Answer : Hermetic sealed compressor: A hermetic sealed compressor is one in which both compressor and motor are confined in a single outer welded steel shell. The motor and compressor are directly coupled ... sealed compressors have very long life. 7) The leakage of refrigerant is completely avoided.

Effect Of Superheating of suction Vapour-(before compression)

Description : Effect Of Superheating of suction Vapour-(before compression)

Last Answer : Effect Of Superheating of suction Vapour-(before compression) A vapour compression cycle with superheated vapour before compression is shown on T-s and p-h diagrams respectively. In this cycle, the ... . Thus, to avoid this, a 5 to 20 K superheat of the refrigerant is always desirable. 

Global Warming

Description : Global Warming

Last Answer : Global Warming: It is also affects on climate. It refers to the long term fluctuations in Temperature, precipitation, wind and earth elements of the earth climate system. The effects of global warming ... Changes (IPCC) projects increase in average global temperatures ranging from 1.4 0C to 5.8 0C

Green House Effect

Description : Green House Effect

Last Answer : Green House Effect:- It is earth ability to retain heat. When the sun rays reach the planet, approximately two thirds of the thermal energy enters earth's atmosphere and is absorbed by the planet's ... would be nearly 35°C (63°F) colder, and the planet would be much less suitable for human life.

What is the effect of heat on insulating material ?

Description : What is the effect of heat on insulating material ?

Last Answer : With increasing temperature, the resistance of almost all solid insulators except Avro decreases. When the temperature drops again, the resistance increases.

Biological functions of lipids include (A) Source of energy (B) Insulating material (C) Maintenance of cellular integrity (D) All of these

Description : Biological functions of lipids include (A) Source of energy (B) Insulating material (C) Maintenance of cellular integrity (D) All of these

Last Answer : Answer : D

Which of the following statements best describes the material known as varnished cambric? A. Felted asbestos sealed with varnish. B. Cotton cloth coated with insulating varnish. C. Rubber insulation coated with a layer of tin. D. Paper impregnated with mineral oil, specially wrapped with nonmetallic tape, and coated with varnish.

Description : Which of the following statements best describes the material known as varnished cambric? A. Felted asbestos sealed with varnish. B. Cotton cloth coated with insulating varnish. C. Rubber ... Paper impregnated with mineral oil, specially wrapped with nonmetallic tape, and coated with varnish.

Last Answer : Answer: B

A circuit breaker differs from a fuse in that a circuit breaker _____________. A. melts and must be replaced B. is enclosed in a tube of insulating material with metal ferrules at each end C. gives no visual indication of having opened the circuit D. trips to break the circuit and may be reset

Description : A circuit breaker differs from a fuse in that a circuit breaker _____________. A. melts and must be replaced B. is enclosed in a tube of insulating material with metal ferrules at each end C. gives no visual indication of having opened the circuit D. trips to break the circuit and may be reset

Last Answer : Answer: D

Which of the following is the most widely used insulating material for steam carrying pipelines? (A) Ceramic fibre blanket (B) Glass wool and 85% magnesia (C) Vermiculite (D) Slag wool

Description : Which of the following is the most widely used insulating material for steam carrying pipelines? (A) Ceramic fibre blanket (B) Glass wool and 85% magnesia (C) Vermiculite (D) Slag wool

Last Answer : (B) Glass wool and 85% magnesia

The compound of silicon used as insulating material for electric motors/appliances is

Description : The compound of silicon used as insulating material for electric motors/appliances is

Last Answer : silicone.

The critical radius of insulation for a spherical shell is (where, K = thermal conductivity of insulating material h0 = heat transfer coefficient at the outer surface) (A) K/h0 (B) 2K/h0 (C) h0 /K (D) h0 /2K

Description : The critical radius of insulation for a spherical shell is (where, K = thermal conductivity of insulating material h0 = heat transfer coefficient at the outer surface) (A) K/h0 (B) 2K/h0 (C) h0 /K (D) h0 /2K

Last Answer : (B) 2K/h0

What do you understand by tan delta for a insulating material?

Description : What do you understand by tan delta for a insulating material?

Last Answer : Tan delta measurement is done to find the qualities of insulating material. Tan delta is angle between current due to surface leakage or current due to capacitance and the capacitive current. That is Tan δ = Ir / Ic. 

Which of the following is the most widely used heat insulating material for pipelines carrying steam? (A) Tar dolomite bricks followed by asbestos (B) Fireclay refractory followed by aluminium sheet (C) Cotton followed by aluminium foil (D) 85% magnesia cement and glass wool

Description : Which of the following is the most widely used heat insulating material for pipelines carrying steam? (A) Tar dolomite bricks followed by asbestos (B) Fireclay refractory followed by aluminium sheet (C) Cotton followed by aluminium foil (D) 85% magnesia cement and glass wool

Last Answer : (D) 85% magnesia cement and glass wool

What is the major factor that makes coaxial cable less susceptible to noisethan twisted-pair cable? A) inner conductor B) diameterof cable C) outer conductor D) insulating material

Description : What is the major factor that makes coaxial cable less susceptible to noisethan twisted-pair cable? A) inner conductor B) diameterof cable C) outer conductor D) insulating material

Last Answer : outer conductor

A steam pipe is intended to be insulated with two layers of insulating materials of different thermal conductivities. For minimum heat transfer to take place (A) The better insulation material should be put just next to pipe (i.e., inside) (B) The better insulating material should be put outside (C) Either of the insulating material could be put on either side (D) Steam temperature is considered before deciding as to which insulating material is to be put inside (i.e., just next to the pipe)

Description : A steam pipe is intended to be insulated with two layers of insulating materials of different thermal conductivities. For minimum heat transfer to take place (A) The better insulation material should be put just ... to which insulating material is to be put inside (i.e., just next to the pipe)

Last Answer : (A) The better insulation material should be put just next to pipe (i.e., inside)

Dielectric (A) Is an electrical insulating material (B) Of low resistivity is preferred (C) Should have high thermal conductivity (D) Need not defy the corrosive action of chemicals

Description : Dielectric (A) Is an electrical insulating material (B) Of low resistivity is preferred (C) Should have high thermal conductivity (D) Need not defy the corrosive action of chemicals

Last Answer : (A) Is an electrical insulating material

A steam carrying pipeline is insulated with two layers of insulating materials with the inferior insulation material forming the inner part. If the two insulating layers are interchanged, the heat conducted will (A) Increase (B) Decrease (C) Remain unaffected (D) May increase or decrease; depends on the thickness of each layer

Description : A steam carrying pipeline is insulated with two layers of insulating materials with the inferior insulation material forming the inner part. If the two insulating layers are interchanged, the heat conducted ... ) Remain unaffected (D) May increase or decrease; depends on the thickness of each layer

Last Answer : Option C

The disadvantage with paper as insulating material is (a) it is hygroscopic (6) it has high capacitance (c) it is an organic material (d) none of the above

Description : The disadvantage with paper as insulating material is (a) it is hygroscopic (6) it has high capacitance (c) it is an organic material (d) none of the above

Last Answer : (a) it is hygroscopic

The insulating material should have (a) low permittivity (b) high resistivity (c) high dielectric strength (d) all of the above

Description : The insulating material should have (a) low permittivity (b) high resistivity (c) high dielectric strength (d) all of the above

Last Answer : (d) all of the above

The insulating material for a cable should have (a) low cost (b) high dielectric strength (c) high mechanical strength (d) all of the above

Description : The insulating material for a cable should have (a) low cost (b) high dielectric strength (c) high mechanical strength (d) all of the above

Last Answer : (d) all of the above

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.

If an insulating material is operated beyond the maximum allowable temperature, its life is (a) drastically increased (b) drastically reduced (c) unaffected (d) none of the above

Description : If an insulating material is operated beyond the maximum allowable temperature, its life is (a) drastically increased (b) drastically reduced (c) unaffected (d) none of the above

Last Answer : (b) drastically reduced

The insulating material used between the commutator segments is normally (a) graphite (b) paper (c) mica (d) insulating varnish

Description : The insulating material used between the commutator segments is normally (a) graphite (b) paper (c) mica (d) insulating varnish

Last Answer : Ans: c

Selection of Insulating Material Practical

Description : Selection of Insulating Material Practical 

Last Answer : Practical Significance The identification and selection of proper insulating materials is required for safe working of electrical appliances. The insulating material separates the electrical conductors ... the material for proper application and write the application in observation space.

Define dielectric failure of electrical insulating material.

Description : Define dielectric failure of electrical insulating material. 

Last Answer : Definition of dielectric failure of electrical insulating material. In the insulating material if the applied voltage is increased gradually then for certain value insulation will break down, ... material vanishes its insulating properties and starts conducting, also known as dielectric failure.

State any two applications of gaseous insulating material used in switchgears.

Description : State any two applications of gaseous insulating material used in switchgears. 

Last Answer : Applications of gaseous insulating material used in switchgears:   1. Non inflammable material (gas) in switchgear. 2. High dielectrical strength material in electrical machine. 3. As a cooling agent in circuit breaker

State failure phenomena observed in insulating material. State four reasons for failure of gaseous and solid dielectric materials.

Description : State failure phenomena observed in insulating material. State four reasons for failure of gaseous and solid dielectric materials. 

Last Answer : Failure phenomena in insulating material means the dielectric property fails :  The dielectric failure mean the dielectric strength of insulating material reduces due to high voltages or high ... 6. Due to poor maintenance of insulating material there may be possibility dielectric failure 

State two applications of : (i) PVC paper (ii) Porcelain with type of class based on withstand temperature is insulating material.

Description : State two applications of : (i) PVC paper (ii) Porcelain with type of class based on withstand temperature is insulating material. 

Last Answer :  (i) Application of PVC paper : 1. It is used in slot lining or motor winding insulation purpose 2. For Insulation of Transformer winding (ii) Application of Porcelain : 1. Mainly used for manufacturing ... on withstand temperature : * H' & C' Class of insulation i e. 180° and above 180°C 

State gaseous and liquid insulating material.

Description : State gaseous and liquid insulating material.

Last Answer : i) Gaseous insulating material : 1. Air 2. Nitrogen 3. Hydrogen 4. SF6 ii) liquid insulating material: 1. Transformer oil 2. Capacitor oil 3. Cable oil 4. Pyranol 5. Savotal 6. Savol 7. Vegetable oil 8. Silicon liquids

Explain the requirements of good insulating material.

Description : Explain the requirements of good insulating material.

Last Answer : Requirement of good insulating material are: i) Electrical ii) Mechanical iii) Thermal iv) Chemical (i) Electrical requirement: A good insulating material should have high resistivity and low ... alkalies. It should not absorb water as water reduces insulation resistance and dielectric strength.

Based on temperature withstanding ability, classify insulating material.

Description : Based on temperature withstanding ability, classify insulating material. 

Last Answer : class Temperature withstanding ability in 0C Materials Y 90 Cotton, silk paper and similar organic materials neither impregnated nor immersed in any oil, rubber, PVC. A 105 ... rubber compounds C Above 180  Mica, ceramics, glass, Teflon, quartz, etc.