Drinks remain hot or cold for a long time in a thermos flask because of the (a) presence of air, which is a bad conductor of heat, in between the double walls (b) silver coating on the inside of the double walls (c) vacuum between the double walls (d) combined effects of (b) and (c)

Drinks remain hot or cold for a long time in a thermos flask because of the (a) presence of air, which is a bad conductor of heat, in between the double walls (b) silver coating on the inside of the double walls (c) vacuum between the double walls (d) combined effects of (b) and (c)
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Tea kept in a thermos flask is vigorously shaken. If the tea is considered as a system, then its temperature will (A) Increase (B) Decrease (C) Remain unchanged (D) First fall and then rise

Description : Tea kept in a thermos flask is vigorously shaken. If the tea is considered as a system, then its temperature will (A) Increase (B) Decrease (C) Remain unchanged (D) First fall and then rise

Last Answer : (A) Increase

Why does a liquid remain hot or cold for a long time inside a thermo flask?

Description : Why does a liquid remain hot or cold for a long time inside a thermo flask?

Last Answer : Ans: Because of the presence of air, which is poor conductor of heat, in between the double glass walls of a thermos flask.

It is a very hot day. You are in a special kitchen, in that there are no exits and the walls of this kitchen are thermally very well insulated. If you open the refrigerator door, the room will eventually: w) cool off. x) remain the same. y) heat up.

Description : It is a very hot day. You are in a special kitchen, in that there are no exits and the walls of this kitchen are thermally very well insulated. If you open the refrigerator door, the room will eventually: w) cool off. x) remain the same. y) heat up.

Last Answer : ANSWER: Y -- HEAT UP.

Emphysema is described as: a) A disease of the airways characterized by destruction of the walls of overdistended alveoli. Emphysema is a category of COPD. b) A disease that results in a common clinical outcome of reversible airflow obstruction. Asthma is the disease described. c) The presence of cough and sputum production for at least a combined total of two or three months in each of two consecutive years. Bronchitis is the disease described. d) Chronic dilatation of a bronchus or bronchi Bronchiectasis is the condition described.

Description : Emphysema is described as: a) A disease of the airways characterized by destruction of the walls of overdistended alveoli. Emphysema is a category of COPD. b) A disease that results in ... disease described. d) Chronic dilatation of a bronchus or bronchi Bronchiectasis is the condition described.

Last Answer : a) A disease of the airways characterized by destruction of the walls of overdistended alveoli. Emphysema is a category of COPD.

A pyrex tumbler does not crack when hot water is poured into it because pyrex (a) is a strong material (b) does not expand much on heating (c) is a good conductor of heat (d) expands equally from inside and outside

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Last Answer : Ans:(b)

When hot liquid is poured into a thick glass tumbler, it cracks because glass – (1) is a bad conductor of heat so only inner surface expands (2) has high temperature coefficient of expansion (3) has a very low specific heat (4) has low temperature coefficient of expansion

Description : When hot liquid is poured into a thick glass tumbler, it cracks because glass – (1) is a bad conductor of heat so only inner surface expands (2) has high temperature coefficient of expansion (3) has a very low specific heat (4) has low temperature coefficient of expansion

Last Answer : (1) is a bad conductor of heat so only inner surface expands Explanation: When hot liquid is poured into a thick glass tumbler, it cracks because glass is a bad conductor of heat so only inner surface expands.

When hot liquid is poured into a thick glass tumbler, it cracks because glass : (1) is a bad conductor of heat so only inner surface expands (2) has high temperature coefficient of expansion (3) has a very low specific heat (4) has low temperature coefficient of expansion

Description : When hot liquid is poured into a thick glass tumbler, it cracks because glass : (1) is a bad conductor of heat so only inner surface expands (2) has high temperature coefficient of expansion (3) has a very low specific heat (4) has low temperature coefficient of expansion

Last Answer :  is a bad conductor of heat so only inner surface expands 

How does the flow of air occur in natural draught cooling towers? a) Natural pressure head density between cold outside air and humid inside air b) Variation in pressure of both cold outside air and humid inside air c) Due to the given air vents and vacuum ports d) Because of difference in the volume of both the of airs

Description : How does the flow of air occur in natural draught cooling towers? a) Natural pressure head density between cold outside air and humid inside air b) Variation in pressure of both cold outside air and ... given air vents and vacuum ports d) Because of difference in the volume of both the of airs

Last Answer : Natural pressure head density between cold outside air and humid inside air

How does the flow of air occur in natural draught cooling towers? a) Natural pressure head density between cold outside air and humid inside air b) Variation in pressure of both cold outside air and humid inside air c) Due to the given air vents and vacuum ports d) Because of difference in the volume of both the of airs

Description : How does the flow of air occur in natural draught cooling towers? a) Natural pressure head density between cold outside air and humid inside air b) Variation in pressure of both cold outside air and ... given air vents and vacuum ports d) Because of difference in the volume of both the of airs

Last Answer : Natural pressure head density between cold outside air and humid inside air

I need recommendations for a thermos to keep food hot?

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Will the stainless thermos keep food hot?

Description : Will the stainless thermos keep food hot?

Last Answer : Yes the stainless thermos will keep food hot. They also are more sturdy.

How to clean the inside of a thermos

Description : I can't get inside anything. There is a dark coating.

Last Answer : citric acid and hot water vinegar and hot water baking soda and hot water

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Last Answer : They should be applied separately, the acid and flux are weakening each other mixed together like that. Although they perform two separate functions in the process, both functions are necessary and are being weakened by mixing the two chemicals. You may have problems with the plating flaking off.

In a gas-liquid shell and tube heat exchanger, the(A) Presence of a non-condensable gas decreases the condensing film co￾efficient (B) Gases under high pressure are routed through the tube side, because high pressure gases are corrosive in nature (C) Gases to be heated/cooled is normally routed through the shell side, because the corrosion caused by the cooling water or steam condensate remain localised to the tubes (D) All 'a', 'b' & 'c'

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Last Answer : (D) All 'a', 'b' & 'c'

Presence of free moisture in coal during its high temperature carbonisation (A) Reduces the coking time (B) Protects the volatile products from pyrolysis (cracking) in the presence of hot coke and hot oven walls (C) Increases the loss of fine coal dust from the ovens when charging (D) None of these

Description : Presence of free moisture in coal during its high temperature carbonisation (A) Reduces the coking time (B) Protects the volatile products from pyrolysis (cracking) in the presence of hot coke and hot oven walls (C) Increases the loss of fine coal dust from the ovens when charging (D) None of these

Last Answer : (B) Protects the volatile products from pyrolysis (cracking) in the presence of hot coke and hot oven walls

Does the human body favor drinking hot-warm drinks versus frozen-cold beverages?

Description : Does the human body favor drinking hot-warm drinks versus frozen-cold beverages?

Last Answer : I was told that it takes energy to cool down or warm up liquids that are consumed, and that drinks at body temperature are absorbed faster.

Do you prefer your drinks hot or cold?

Description : Do you prefer your drinks hot or cold?

Last Answer : Well, ever since my childhood, I have never been comfortable with taking or consuming anything that is hot for any reason whatsoever. It never goes well with me because I easily get injured in the mouth ... before making the tea or I would allow the hot water to cool down before making the tea.

The most accurate finding of pulpal pathology A. Radiolucency on the apical region B. Pain on hot or cold drinks C. he absence of response to pulp testing

Description : The most accurate finding of pulpal pathology A. Radiolucency on the apical region B. Pain on hot or cold drinks C. he absence of response to pulp testing

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A patient comes to you with medium pain of tooth filled with Composite resin as a result of cold or hot drinks, what will your initial management be, A. Remove the restorative material and start an Endontic treatment B. Remove the restorative material and place a sedative temporary material C. Place a coat of bonding material on the old composite

Description : A patient comes to you with medium pain of tooth filled with Composite resin as a result of cold or hot drinks, what will your initial management be, A. Remove the restorative material and ... material and place a sedative temporary material C. Place a coat of bonding material on the old composite

Last Answer : B. Remove the restorative material and place a sedative temporary material

The capacity of double-effect evaporator is less than half of the capacity of two single effects, each of which is operating over same terminal temperature difference, when the (A) Solution has an elevation of boiling point (B) Evaporators operate under vacuum (C) Evaporators operate at atmospheric pressure (D) None of these

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Last Answer : (A) Solution has an elevation of boiling point

Sherardizing process is used for (A) Surface coating (B) Heat treatment of high speed steel (C) Cold working on metals (D) None of these

Description : Sherardizing process is used for (A) Surface coating (B) Heat treatment of high speed steel (C) Cold working on metals (D) None of these

Last Answer : (A) Surface coating

In cold countries alcohol is preferred to mercury as a thermometric liquid because (a) alcohol is a better conductor of heat (b) alcohol can be coloured and its level seen easily (c) alcohol has a lower freezing point than mercury (d) alcohol is cheaper than mercury

Description : In cold countries alcohol is preferred to mercury as a thermometric liquid because (a) alcohol is a better conductor of heat (b) alcohol can be coloured and its level seen easily (c) alcohol has a lower freezing point than mercury (d) alcohol is cheaper than mercury

Last Answer : Ans:(c)

Woollen cloth protects the body from cold because – (1) it is a good conductor of heat (2) it is a poor conductor of heat (3) external heat rays enter into the body through the woollen cloth (4) it reflects heat

Description : Woollen cloth protects the body from cold because – (1) it is a good conductor of heat (2) it is a poor conductor of heat (3) external heat rays enter into the body through the woollen cloth (4) it reflects heat

Last Answer : (2) it is a poor conductor of heat Explanation: It is just because woolen clothes have fibres and between those fibres air is trapped which reduces heat loss. It reduces heat loss because it is an insulator or poor conductor of heat.

Woollen cloth protects the body from cold because – (1) it is a good conductor of heat (2) it is a poor conductor of heat (3) external heat rays enter into the body through the woollen cloth (4) it reflects heat

Description : Woollen cloth protects the body from cold because – (1) it is a good conductor of heat (2) it is a poor conductor of heat (3) external heat rays enter into the body through the woollen cloth (4) it reflects heat

Last Answer : (2) it is a poor conductor of heat Explanation: It is just because woolen clothes have fibres and between those fibres air is trapped which reduces heat loss. It reduces heat loss because it is an insulator or poor conductor of heat.

Woollen cloth protects the body from cold because (1) it is a good conductor of heat (2) it is a poor conductor of heat (3) external heat rays enter into the body through the woollen cloth (4) it reflects heat

Description : Woollen cloth protects the body from cold because (1) it is a good conductor of heat (2) it is a poor conductor of heat (3) external heat rays enter into the body through the woollen cloth (4) it reflects heat

Last Answer :  it is a poor conductor of heat

Fish can survive inside a frozen lake because (a) fish are warm blooded animals (b) fish hibernate in ice (c) water near the bottom does not freeze (d) ice is a good conductor of heat

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Last Answer : Ans:(c)

What do you clean your tile shower walls with if your cat drinks from the puddles?

Description : What do you clean your tile shower walls with if your cat drinks from the puddles?

Last Answer : answer:I clean my house with vinegar and water only. After a shower, I collect the hair in a rubber drainer and let a little clean water flow all over the shower stall. My cat drinks ... It is part of our routine, several times a day and predictably during my morning and bedtime ablutions..

The inner portion of the fiber cable is called a. Cladding b. Coating c. Inner conductor d. Core

Description : The inner portion of the fiber cable is called a. Cladding b. Coating c. Inner conductor d. Core

Last Answer : d. Core

Metal tea pots have wooden handles because – (1) wood is a bad conductor of heat (2) it prevents electric shock (3) it gives beauty to the pots (4) it is hygienic

Description : Metal tea pots have wooden handles because – (1) wood is a bad conductor of heat (2) it prevents electric shock (3) it gives beauty to the pots (4) it is hygienic

Last Answer : (2) it prevents electric shock Explanation: Wood is a bad conductor of heat due to the arrangement of its molecules. As the molecules of wood are far from each other, they cannot pass heat through them.

Metal tea pots have wooden handles because – (1) wood is a bad conductor of heat (2) it prevents electric shock (3) it gives beauty to the pots (4) it is hygienic

Description : Metal tea pots have wooden handles because – (1) wood is a bad conductor of heat (2) it prevents electric shock (3) it gives beauty to the pots (4) it is hygienic

Last Answer : (2) it prevents electric shock Explanation: Wood is a bad conductor of heat due to the arrangement of its molecules. As the molecules of wood are far from each other, they cannot pass heat through them.

Metal tea pots have wooden handles because (1) wood is a bad conductor of heat (2) it prevents electric shock (3) it gives beauty to the pots (4) it is hygienic

Description : Metal tea pots have wooden handles because (1) wood is a bad conductor of heat (2) it prevents electric shock (3) it gives beauty to the pots (4) it is hygienic

Last Answer :  it prevents electric shock

Wollen clothes keep the body warm because (1) Wool increases the temperature of the body (2) Wool is a bad conductor (3) Wool absorbs radiant heat from outer objects (4) Wool rejects heat from the outer objects

Description : Wollen clothes keep the body warm because (1) Wool increases the temperature of the body (2) Wool is a bad conductor (3) Wool absorbs radiant heat from outer objects (4) Wool rejects heat from the outer objects 

Last Answer :  Wool is a bad conductor

Why does ice coverfed in sawdust ct melt quickly? (1) Sawdust does not allow the air to touch the ice (2) The water is absorbed by sawdust (3) Sawdust is a bad conductor of heat (4) Sawdust is good conductor of heat

Description : Why does ice coverfed in sawdust ct melt quickly? (1) Sawdust does not allow the air to touch the ice (2) The water is absorbed by sawdust (3) Sawdust is a bad conductor of heat (4) Sawdust is good conductor of heat

Last Answer : (3) Sawdust is a bad conductor of heat Explanation: Ice needs to absorb heat energy to melt and become water (called latent heat of fusion). Since saw-dust is a poor conductor of heat, it takes ... required heat energy. This allows ice to remain in solid state for more time when packed in saw dust.

Why does ice covered in sawdust not melt quickly ? (1) Sawdust does not allow the air to touch the ice (2) The water is absorbed by sawdust (3) Sawdust is a bad conductor of heat (4) Sawdust is good conductor of heat

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Last Answer : Sawdust is a bad conductor of heat

A dephlegmator is a (A) Total condenser (B) Vacuum evaporator (C) Partial condenser (D) Double pipe heat exchanger

Description : A dephlegmator is a (A) Total condenser (B) Vacuum evaporator (C) Partial condenser (D) Double pipe heat exchanger

Last Answer : (C) Partial condenser

A student has been collecting silver coins and copper coins. One day she observes a black coating on silver coins and a green coating on copper coins. Which chemical phenomenon is responsible for these coatings? Write the names of black and green coatings.

Description : A student has been collecting silver coins and copper coins. One day she observes a black coating on silver coins and a green coating on copper coins. Which chemical phenomenon is responsible for these coatings? Write the names of black and green coatings.

Last Answer : The phenomenon is called corrosion. Silver gets tarnished when exposed to atmosphere which forms a black coating of silver oxide. Copper forms a green deposit on its surface when exposed to moist air. The green coating is copper sulphate.

Galvanised Iron sheets have a coating of------ A. Tin B. Silver C. Zinc (Answer) D. Chromium

Description : Galvanised Iron sheets have a coating of------ A. Tin B. Silver C. Zinc (Answer) D. Chromium

Last Answer : C. Zinc (Answer)

What is a flat sheet of glass with a silver-colored coating?

Description : What is a flat sheet of glass with a silver-colored coating?

Last Answer : It is a mirror or a looking glass

Clavulanic acid is combined with amoxicillin because (a) It kills bacteria that are not killed by-moxicillin (b) It reduces renal clearance of amoxicillin (c) It counteracts the adverse effects of amoxicillin (d) It inhibits beta lactamases that destroy amoxicillin

Description : Clavulanic acid is combined with amoxicillin because (a) It kills bacteria that are not killed by-moxicillin (b) It reduces renal clearance of amoxicillin (c) It counteracts the adverse effects of amoxicillin (d) It inhibits beta lactamases that destroy amoxicillin

Last Answer : Ans: D

Clavulanic acid is combined with amoxicillin because: A. It kills bacteria that are not killed by amoxicillin B. It retards renal excretion of amoxicillin C. It counteracts the adverse effects of amoxicillin D. It inhibits beta lactamases that destroy amoxicillin

Description : Clavulanic acid is combined with amoxicillin because: A. It kills bacteria that are not killed by amoxicillin B. It retards renal excretion of amoxicillin C. It counteracts the adverse effects of amoxicillin D. It inhibits beta lactamases that destroy amoxicillin

Last Answer : D. It inhibits beta lactamases that destroy amoxicillin

A progestin and an estrogen are combined in oral contraceptive pill because: A. The estrogen blocks the side effects of the progestin B. The progestin blocks the side effects of the estrogen C. Both synergise to suppress ovulation D. Both synergise to produce hostile cervical mucus

Description : A progestin and an estrogen are combined in oral contraceptive pill because: A. The estrogen blocks the side effects of the progestin B. The progestin blocks the side effects of the estrogen C. Both synergise to suppress ovulation D. Both synergise to produce hostile cervical mucus

Last Answer : C. Both synergise to suppress ovulation

The progestin used in combined oral contraceptive pill is a 19-nortestosterone derivative because: A. They have potent antiovulatory action of their own B. They do not produce any metabolic effects C. They produce fewer side effects D. They are longer acting

Description : The progestin used in combined oral contraceptive pill is a 19-nortestosterone derivative because: A. They have potent antiovulatory action of their own B. They do not produce any metabolic effects C. They produce fewer side effects D. They are longer acting

Last Answer : A. They have potent antiovulatory action of their own

When temperature difference between liquid and its surroundings is doubled, the rate of loss of heat will: (1) remain same (2) double (3) three times (4) four times

Description : When temperature difference between liquid and its surroundings is doubled, the rate of loss of heat will: (1) remain same (2) double (3) three times (4) four times

Last Answer : (2) double Explanation: According to Newton's law of cooling, the rate of loss of heat of a body is directly proportional to the difference between the temperature of hot body and temperature of the surroundings, provided that the difference in temperature is small enough.

In a co-current double pipe heat exchanger used for condensing saturated steam over the inner tube, if the entrance and exit conditions of the coolant are interchanged, then the rate of condensation will (A) Increase (B) Decrease (C) Remain unchanged (D) Either increase or decrease; depends on the coolant flow rate

Description : In a co-current double pipe heat exchanger used for condensing saturated steam over the inner tube, if the entrance and exit conditions of the coolant are interchanged, then the rate of condensation ... Decrease (C) Remain unchanged (D) Either increase or decrease; depends on the coolant flow rate

Last Answer : (C) Remain unchanged

When temperature difference between liquid and its surroundings is doubled, the rate of loss of heat will: (1) remain same (2) double (3) three times (4) four times

Description : When temperature difference between liquid and its surroundings is doubled, the rate of loss of heat will: (1) remain same (2) double (3) three times (4) four times

Last Answer : double

Photographic plates are covered with black paper because (a) the cellulose acetate of the paper must remain fresh (b) sunlight is easily absorbed by black paper and it helps develop the film (c) the silver bromide present on the plate is very sensitive to light and black paper prevents contact with light (d) the conversion of silver bromide to metallic silver is essential

Description : Photographic plates are covered with black paper because (a) the cellulose acetate of the paper must remain fresh (b) sunlight is easily absorbed by black paper and it helps develop the film ... paper prevents contact with light (d) the conversion of silver bromide to metallic silver is essential

Last Answer : Ans:(c)

In severe winter, in cold countries water pipes burst because – (1) Water expands on freezing (2) Contraction of water pipes (3) High atmospheric pressure (4) Combined effect of all the above three

Description : In severe winter, in cold countries water pipes burst because – (1) Water expands on freezing (2) Contraction of water pipes (3) High atmospheric pressure (4) Combined effect of all the above three

Last Answer : (1) Water expands on freezing Explanation: Most liquids have a quite simple behavior when they are cooled (at a fixed pressure): they shrink. The liquid contract as it is cooled; ... substance solidifies, which causes it to contract some more because crystalline solids are usually tightly packed.

In severe winter, in cold countries water pipes burst because (1) water expands on freezing (2) contraction of water pipes (3) high atmospheric pressure (4) combined effect of all the above three

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Last Answer : water expands on freezing

How long do the effects of three drinks last?

Description : How long do the effects of three drinks last?

Last Answer : It depends upon your size, your gender, and your metabolism.