Tag: evs

Quizzes (439) Questions (4580)

Questions Related to evs

Multiple choice evs eat when you need food poisoning and food preservation methods food spoilage, adulteration and preservation food spoilage and adulteration

Car wax is prepared from

  1. Vegetable wax

  2. Animal wax

  3. Mineral wax

  4. All of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A traditional car wax formula usually consists of a blend of carnauba wax, mixed with other waxes, such as beeswax, natural oils, and will sometimes also include petroleum distillates. Carnauba wax is a hard wax obtained from the leaves of a Brazilian palm tree which produces a glassy shine. Carnauba based waxes must be reapplied frequently in order to maintain shine. Beeswax is a durable wax found in honeycombs and used in car wax formulas to provide a protective barrier. Natural oils, such as linseed oil, are emollients use to provide added shine, luster, and protection, to the painted surface. Petroleum distillates are solvents derived from crude oil that make the wax easier to spread and to clean the paint.

So, the correct answer is option D.

Multiple choice evs eat when you need food poisoning and food preservation methods food spoilage, adulteration and preservation food spoilage and adulteration

Apples coated with carbomethylchitosan remains fresh for

  1. $1\ month$
  2. $6\ months$
  3. $1\ year$
  4. $1\ year$ and $6\ months$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Carbonmethylchitosan is the wax-like structure present on the apples like a coating structure. This wax coating is very important in apples because this coating maintains the freshness of apple for a long time is near about 6 to 8 months. This type of chitosan is made by treating the chitin shells and shrimps of other crustaceans with an alkaline substance like sodium hydroxide.
So, the correct option is '6 months'.

Multiple choice evs eat when you need food poisoning and food preservation methods food spoilage, adulteration and preservation food spoilage and adulteration

Pollen grains can be stored in a viable condition for many years in which of the following conditions?

  1. Anaerobic conditions in 0$^o$ C
  2. Liquid nitrogen (-196$^o$ C)
  3. Liquid nitrogen (0$^o$ C)
  4. Liquid hydrogen (196$^o$ C)
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Pollen grains are stored for many years in the liquid nitrogen, having the temperature of -196 degrees of Celsius. This method of saving is called cryopreservation. The low temperature allows storing for a longer period as it reduces the growth rate of cells. The cryoprotective agents delay the aging of the plants and protect the plants from the damages due to cold.
So, the correct answer is 'Liquid nitrogen (-196$^o$ C)'.
Multiple choice evs experiments with water water and its types hard and soft water what floats - what sinks

A sample of water which starts lathering with soap solution on boiling is called temporary hard water.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A temporary hard water can from lather with soap. The ${ Ca }^{ 2+ }/{ Mg }^{ 2+ }$ ions of water displace ${ Na }^{ + }$ or ${ K }^{ + }$ ions from this salts & form insoluble $Ca/Mg$ salts of fatty acids. 

$\because $ it is temporary hard water, lathering of soap is not that difficult.

Multiple choice evs experiments with water water and its types hard and soft water what floats - what sinks

Which of the following has a low calcium and magnesium content?

  1. Soft water

  2. Hard water

  3. Contaminated water

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Soft water is surface water that contains low  concentrations of ions and in particular is low in ions of calcium and magnesium. Soft water naturally occurs where rainfall and the drainage basin of rivers are formed of hard, impervious and calcium poor rocks.

Multiple choice evs experiments with water water and its types hard and soft water what floats - what sinks

What is hard water?

  1. Low mineral content

  2. Contaminated water

  3. High mineral content

  4. Both B and C
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Hard water is water that has high mineral content (in contrast with "soft water"). Hard water is formed when water percolates through deposits of limestone and chalk which are largely made up of calcium and magnesium carbonates. Hard drinking water may have moderate health benefits, but can pose serious problems in industrial settings, where water hardness is monitored to avoid costly breakdowns in boilers, cooling towers, and other equipment that handles water.

Multiple choice evs experiments with water water and its types hard and soft water what floats - what sinks

.................. water does not lather with soap

  1. Hard water

  2. Soft water

  3. Contaminated water

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Hard water does not lather with but instead forms a gooey mass called scum. Hard water is formed when water percolates through deposits of limestone and chalk which are largely made up of calcium and magnesium carbonates.