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प्रश्न
You want to wear your favourite shirt to a party, but the problem is that it is still wet after a wash. What steps would you take to dry it faster?
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उत्तर
The process of drying the shirt can be made faster in the following ways:
- Spread the shirt to increase the surface area which will increase the rate of evaporation.
- Put it in the sun to increase the temperature to increase the rate of evaporation.
- Keep it under the fan to increase the wind speed which increases the rate of evaporation.
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संबंधित प्रश्न
The molecules can move freely anywhere in
Name the terms for the change of a solid into liquid.
Define the following term of Atom .
Define matter. Give four examples of matter.
What is meant by saying that non-metals are brittle ?
Iron powder and sulphur powder were mixed together and divided into two parts A and B. When part A was heated strongly over a burner, then a substance C was formed. The part B was, however, not heated at all. When dilute hydrochloric acid was added to substance C, then gas D was evolved and when dilute hydrochloric acid was added to part B then gas E was evolved.
- What type of substance is B ?
- What type of substance is C ?
- Name the gas (i) D, and (ii) E ?
- State one characteristic property of gas D.
- Write one test to identify gas E.
Which of the two will scatter light : soap solution or sugar solution ? Why ?
Classify the following into solutions, suspensions and colloids :
Soda-water, Milk, Brine, Blood, Ink, Smoke in air, Chalk water mixture, Milk of Magnesia, Shaving cream, Muddy river water.
Define Sol and give one example.
Which of the following are chemical changes and which physical ? Give reason.
- a glass bottle breaking
- coal burning in air
- making a cake
- wool being knitted into a sweater
Name the process which is used in milk dairies to separate cream from milk.
Fill in the following blanks with suitable words :
Immiscible liquids are separated by using a .....................
How would you obtain sodium chloride from a mixture of sodium chloride and sulphur without using water ?
How is the impurity of iron present in several substances removed in industries ?
Describe the method of separating a mixture containing common salt, sand and ammonium chloride.
The liquid air has three components X, Y and Z whose boiling points are : –186°C, –183°C and –196°C,
respectively. When liquid air is fed into a tall fractional distillation column from near its bottom and warmed
up slowly :
(a) Which component will be collected from near the bottom of the fraction distillation column ? Why ?
(b) Which component will be collected from the top part of the fractional distillation column ? Why ?
(c) Which component will be collected from the middle part of the fractional distillation column ? Why ?
(d) What could the component X, Y and Z be ?
Select the correct answer from A, B, C, D & E for the statement given below:
An atom or group of atoms _________ having a resultant charge.
Stars including Sun are covered in ______.
Liquids have ______.
Give an example of liquid in gas.
