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प्रश्न
What type of magnet is fitted on a crane to separate scrap iron objects from a heap of waste materials in factories ?
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उत्तर
Electromagnets are fitted in cranes to separate scrap iron objects from a heap of waste material in factories.
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संबंधित प्रश्न
Define matter.
Write true or false for each statement. Rewrite the false statement correctly.
Matter cannot exist in different states.
Explain why, osmosis can be considered to be a special kind of diffusion. Classify the following into
(i) osmosis, and (ii) diffusion :
- swelling up of a raisin on keeping in water
- spreading of virus on sneezing
- earthworm dying on coming in contact with common salt
- shrinking of grapes kept in thick sugar syrup
- preserving of pickles in salt
- spreading of smell of cake being baked in the kitchen
- aquatic animals using oxygen dissolved in water during respiration
Classify the following into elements and compounds :
- H2O
- He
- Cl2
- CO
- Co
What is the other name for impure substances ? Give two examples of impure substances.
Explain why, hydrogen and oxygen are considered elements whereas water is not considered an element.
Name a metal which can be easily cut with a knife.
Classify the following into metals, non-metals and metalloids:
Silicon, Mercury, Diamond, Sulphur, Iodine, Germanium, Sodium, Carbon, Magnesium, Copper, Boron, Helium
There are three substances X, Y and Z. The substance X does not have a fixed melting point or boiling point and it still shows the individual properties of its constituents. The substance Y is a pure substance which occurs in nature as such. The substance Y has a fixed melting point and boiling point but it cannot be broken down into simpler substances by any chemical means. The substance Z is also a pure substance whose properties are entirely different from those of its constituents. The substance Z can, however, be divided by electrolysis into two substances which belong to the same class of substances as Y.
- What type of substance could X be ? Name one substance like X.
- What type of substance could Y be ? Name one substance like Y.
- What type of substance could Z be ? Name one substance like Z.
- Which process involves absorption or release of an appreciable amount of energy : formation of substance X or formation of substance Z ?
- Name the three groups into which all the substances like Y are divided on the basis of their properties.
State whether the following statement is true or false :
Bread is an example of solid foam.
How will you differentiate between a suspension and a colloid ?
Define solubility of a substance. How does it vary with temperature ?
What is the effect of temperature on the solubility of solids in liquids ?
One of the following liquids will leave behind a residue on heating. This one is :
How will you separate a mixture containing sand and sugar ?
Describe the various steps involved in the separation of iodine, iron filings and salt from a mixture.
The non S I and S I units of some physical quantities are given in column A and column B respectively. Match the units belonging to the same physical quantity:
| (A) | (B) | ||
| (a) | degree celsius | (i) | kilogram |
| (b) | centimetre | (ii) | pascal |
| (c) | gram per centimetre cube | (iii) | metre |
| (d) | bar | (iv) | kelvin |
| (e) | milligram | (v) | kilogram per metre cube |
The fluidity of solids: ______.
Define the term matter.
Write a scientific reason.
Lemon sherbat has sweet, sour and salty taste and it can be poured in a glass.
