Class 8 Science - Chapter Some Natural Phenomena NCERT Solutions | Name the scale on which the destructive

Describe with the help of a diagram an instrument which can be used to detect a charged body.

Explain why a charged body loses its charge if we touch it with our hand.

Suggest three measures to protect ourselves from lightning.

Suppose you are outside your home and an earthquake strikes. What precaution would you take to protect yourself?

Sometime, a crackling sound is heard while taking off sweater during winters. Explain.

Explain why a charged balloon is repelled by another charged balloon whereas an uncharged balloon is attracted by another charged balloon?

List three states in India where earthquakes are more likely to strike.

When a glass rod is rubbed with a piece of silk cloth the rod
(a) and the cloth both acquire positive charge.
(b) becomes positively charged while the cloth has a negative charge.
(c) and the cloth both acquire negative charge.
(d) becomes negatively charged while the cloth has a positive charge.

Which of the following cannot be charged easily by friction?
(a) A plastic scale
(b) A copper rod
(c) An inflated balloon
(d) A woollen cloth.

The weather department has predicted that a thunderstorm is likely to occur on a certain day. Suppose you have to go out on that day. Would you carry an umbrella? Explain.

Which of the following can be beaten into thin sheets?
  (a) Zinc     (b) Phosphorus     (c) Sulphur     (d) Oxygen

Fill in the blanks
(a) Most liquids that conduct electricity are solutions of , ______________ and ______________.
(b) The passage of an electric current through a solution causes ______________ effects.
(c) If you pass current through copper sulphate solution, copper gets deposited on the plate connected to the terminal of the battery.
(d) The process of depositing a layer ofany desired metal on another material by means of electricity is called .

Give two examples each of situations in which you push or pull to change the state of motion of objects.

Fill in the blanks:
(a) Friction opposes the _____________ between the surfaces in contact with each other.
(b) Friction depends on the _____________ of surfaces.                                                                                                                                                                      (c) Friction produces __________.
(d) Sprinkling of powder on the carrom board ________ friction.
(e) Sliding friction is ___________ than the static friction.

List conditions under which combustion can take place.

Indicate whether the following statements are True (T) or False (F).
(a) Unicellular organisms have one-celled body. (T/F)
(b) Muscle cells are branched. (T/F)
(c) The basic living unit of an organism is an organ. (T/F)
(d) Amoeba has irregular shape. (T/F)

Fill in the blanks:
(a) A place where animals are protected in their natural habitat is called                  .
(b) Species found only in a particular area is known as                          .
(c) Migratory birds fly to far away places because of                     changes.

Suppose you are in a dark room. Can you see objects in the room? Can you see objects outside the room. Explain.

What are the different ways in which water gets contaminated ?

Explain the importance of reproduction in organisms.

Complete the cross-word puzzle using the hints given below

Across
    1. The process of the fusion of the gametes.
    6. The type of fertilization in hen.
    7. The term used for bulges observed on the sides of the body of Hydra.
    8. Eggs are produced here.

Down
    2. Sperms are produced in these male reproductive organs.
    3. Another term for the fertilized egg.
    4. These animals lay eggs.
    5. A type of fission in amoeba.

List conditions under which combustion can take place.

Write a short paragraph on the harms caused by microorganisms.

Suppose you are in a dark room. Can you see objects in the room? Can you see objects outside the room. Explain.

Name the largest planet of the solar system.

Explain why sportsmen use shoes with spikes.

Lightning and thunder take place in the sky at the same time and at the same distance from us. Lightning is seen earlier and thunder is heard later. Can you explain?

In case of a fire, before the firemen use the water hoses, they shut off the main electrical supply for the area. Explain why they do this.

Explain how fertilisers are different from manure.

Match items in column A with one or more items in column B:

A                                           B
(i) Inner planets                 (a) Saturn
(ii) Outer planets               (b) Pole Star
(iii) Constellation               (c) Great Bear
(iv) Satellite of the Earth   (d) Moon
                                          (e) Earth
                                          (f) Orion
                                          (g) Mars