Thursday, November 29, 2012

8th Some Natural Phenomenon-Lightening and Earthquake

CBSE CLASS CHAPTER NO.15 SOME NATURAL PHENOMENA:Question Banks

1. How many types of charges exist?

a. One b. Three c. Two d. Four

2. Who invented the lightning conductor?

a. Alexander Fleming b. Graham Bell

c. Benjamin Franklin d. Thomas Alva Edison

3. What device is used to protect building from lightning?

a. Crescograph

b. Anemometer

c. Lightning Conductor

d. Barometer

4. What scale is used to measure the magnitude of earthquake?

a. Richter b. Celsius c. Fahrenheit d. Kilogram

5. The magnitude of earthquakes that occurred at Bhuj and

Kashmir were

a. less than 4

b. less than 2

c. less than 6

d. Higher than 7

6. Name 2 natural phenomena which cause us heavy damage.

7. Why were the people of ancient times afraid of lightning?

8. What is lightning due to?

9. What was the discovery made by Ancient Greeks?

10. List two daily life examples where charges are produced.

11. What are charged objects?

12. How can you charge the following objects?

a. glass rod                    b. Ebonite rod

13. How can we get the following charges?

a. Positive charge         b. Negative charge

14. What is the principle of an electroscope?

15. Distinguish static electricity from electric current.

16. Like charges _________ and unlike charges ____________each other.

17. What is an earthquake?

18. The weak zones where earthquakes occur are called _____________ zones.

19. A lightning conductor provides a ______ ______ for the  transfer of charges to the ground.

20. The magnitudes of earthquakes lesser than ___________ on Richter scale does not cause severe damage.

21. What are the various causes for earth quakes?

22. Write any three harmful effects of an earthquake.

23. Name the three layers of the earth.

24. Suggest any 3 measures to protect ourselves from lightning.

25. Rearrange the steps in the formation of lightning in the form of a flow chart.  

Air become charged, accumulation of charges, movements of air currents and water droplets, streaks of light and sound are produced.

Further solved questions:

2 comments:

  1. You may also view -> Some Natural Phenomenon E-Notes Download

    ReplyDelete
  2. The gold-leaf electroscope was developed in 1787 by British clergyman and physicist Abraham Bennet.
    A gold-leaf electroscope is a simple device which is used to identify the electric charge present in a body.
    Construction of Electroscope
    It consists of a vertical metal rod, usually brass, from the end of which hang two parallel strips of thin flexible gold leaf. A disk or ball terminal is attached to the top of the rod, where the charge to be tested is applied.

    Working of Electroscope :(a) If an uncharged body is brought and touched on the metallic disk, we notice no change in the golden leaves.
    (b) If a charged body (positively or negatively charged) is brought and touched to the metallic disk of the gold-leaf electroscope, it attains the same charge as that of the charged body touched to the metallic disk by the property of transmission of charges from one charged substance to another substance.
    (c) Therefore, the golden leaves in the electroscope also attain like charges and diverge from each other due to the repulsion.
    (d) The repulsion of the golden leaves in the electroscope is the test for finding out that whether a body is charged or not.
    (e) If we touch any of the charred bodies, the charge escapes from our body directly to the earth through our legs.
    (f) The charged body thus loses its charge and becomes neutral.

    ReplyDelete

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