NCERT Class VIII Science Solutions: Chapter 15-Some Natural Phenomena Part 2

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Question 6:

Name the scale on which the destructive energy of an earthquake is measured. An earthquake measures 3 on this scale. Would it be recorded by a seismograph? Is it likely to cause much damage?

Answer:

Richter scale measures the destructive energy of an earthquake. Yes, seismograph can measure an earthquake of magnitude 3 on Richter scale. It is of low intensity and will not cause any damage.

Image result for richter scale

Richter Scale

Question 7:

Suggest three measures to protect ourselves from lightning.

Answer:

Safety Measures during Lightning:

  • Open space is dangerous. Take cover under a building.

  • Thunder storm is an indication to rush for safer place.

  • Once thundering stops, move out to an open place.

Question 8:

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

Answer:

Two charged balloons have similar charges on the surfaces. Since like charges repel each other, that's why one charged balloon is repelled by another charged balloon. When an uncharged balloon is brought near a charged one, the uncharged balloon acquires some opposite charge. Since unlike charges attract each other, therefore a charged balloon attracts an uncharged one.

This image shows thread with uncharged ballons and charged b …

Charged and Uncharged Balloons

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