☰
✕

Is Matter Around Us Pure
Question
Wired Faculty App

Distinguish between mechanical and electromagnetic waves.

Answer

Differences between mechanical and electromagnetic waves are:

Mechanical waves

Electromagnetic waves

1. The waves require a material medium for their propagation.

1. These waves do not require a material medium for their propagation.

2. These are caused due to vibrations of the particles of the medium. 

2. These are caused due to varying electric and magnetic fields.

3. These waves have low speeds, e.g. speed of sound in air is 332 m/s at 0°C.

3. These waves travel with a very high speed of 3 x 108 m/s through vacuum.

4. These waves have usually low frequency and large wavelength.

4. These waves have usually high frequency and low wavelength.

5. These can be transverse or longitudinal.

5. These are only trnasverse waves.

Sponsor Area

Some More Questions From Is Matter Around Us Pure Chapter

Which separation techniques will you apply for the separation of the following?

Different pigments from an extract of flower petals.

Which separation techniques will you apply for the separation of the following?

Butter from curd.

Which separation techniques will you apply for the separation of the following?

Oil from water.

Which separation techniques will you apply for the separation of the following?

Tea leaves from tea

Which separation techniques will you apply for the separation of the following?

Iron pins from sand.

Which separation techniques will you apply for the separation of the following?

Wheat grains from husk

Which separation techniques will you apply for the separation of the following?


Fine mud particles suspended in water.

Write the steps you would use for making tea. Use the words—solution, solvent, solute, dissolve, soluble, insoluble, filtrate and residue.

Pragya tested the solubility of three different substances at different temperatures and collected the data as given below (results are given in the following table, as grams of substance dissolved in 100 grams of water to form a saturated solution).

Substance Dissolved

Temperature in K

283

293

313

333

353

Potassium nitrate

21

32

62

106

107

Sodium chloride

36

36

36

37

37

Potassium chloride

35

35

40

46

54

Ammonium chloride

24

37

41

55

66


What mass of potassium nitrate would be needed to produce a saturated solution of potassium nitrate in 50 grams of water at 313 K?

Pragya makes a saturated solution of potassium chloride in water at 353 K and leaves the solution to cool at room temperature. What would she observe as the solution cools? Explain.

Substance Dissolved

Temperature in K

283

293

313

333

353

Potassium nitrate

21

32

62

106

107

Sodium chloride

36

36

36

37

37

Potassium chloride

35

35

40

46

54

Ammonium chloride

24

37

41

55

66