RBSE Class 8 Science Chapter 15: Natural Phenomena Solutions

Provided here are the RBSE Class 8 Science Chapter 15 Natural Phenomena Solutions. We have also included lots of additional questions, along with their solutions based on the important concepts of the lesson.

Students can utilize these solutions to prepare themselves for the examinations. The RBSE solutions for Class 8 provided here will prove fruitful for the students in excelling in their studies. All these solutions are prepared by our team of experts to give students the best and most accurate solutions to each and every question.

Rajasthan Board Class 8 Science Chapter 15: BYJU’S Important Questions & Answers

RBSE Class 8 Science Chapter 15 Objective Questions: Textbook Important Questions and Solutions

Q1. With the increase in velocity of air, air pressure:

(A) Increases

(B) Decreases

(C) No change

(D) Become double

Answer: (B) Decreases

Q2. What will happen if air blows in between two balloons hanged on wooden stick separated by 10 cm distance:

(A) Balloons come near to each other

(B) Balloons go away from each other

(C) Balloons burst

(D) No change

Answer: (A) Balloons come near to each other

Q3. Centre of cyclone in a calm area is called:

(A) Center

(B) Eye

(C) Head

(D) Tail

Answer: (B) Eye

RBSE Class 8 Science Chapter 15 Fill in the blanks: Textbook Important Questions and Solutions

Q1. Tornado is dark coloured and funnel type ___________.

Answer: clouds

Q2. The air flows from ___________ pressure area to __________ pressure area.

Answer: high, low

Q3. Breeze produces due to ___________ heating of the earth.

Answer: uneven

Q4. The air in motion is called __________.

Answer: wind

RBSE Class 8 Science Chapter 15 Short Answer Type Questions: Textbook Important Questions and Solutions

Q1. How do cyclones form?

Answer: After receiving heat, the water converts into water vapour. This water vapour is converted back into water droplets on condensation.

Warm air near the surface of the ocean rises upwards. This creates a low-pressure area near the surface. This results in the movement of cooler air from the nearby areas into the area where air pressure is low. Now even this cool air becomes moist and warm and moves up. The above cycle keeps continuing. The moist and warm air which rises up, cools the water in the air, resulting in the formation of clouds. This whole system of clouds and winds spins and grows. This entire cycle continues resulting in a cyclone.

Q2. What type of planning is needed to overcome the cyclone?

Answer: Planning that is needed to overcome the cyclone include:

(i) The meteorological department issues forecasts and warnings.

(ii) Water boats, seashores, government institutions, etc. should be promptly made aware of cyclones.

(iii) Government warning should be taken seriously.

(iv) Driving should be avoided on the roads that are submerged in water.

(v) Emergency services phone numbers should be noted down by the people.

(vi) Broken electric wires and switches must not be touched.

(vii) One should help neighbours and friends in need.

Q3. Describe an activity to explain air pressure?

Answer: Here is an activity to explain air pressure:

1. Take a plastic bottle and fill half of the bottle with hot water.

2. Empty the bottle.

3. Immediately close the cap tightly.

4. Now, pour some cold water on the bottle

It is observed that the bottle shrinks.

Why?

This happens because some water vapour of the hot water inside the bottle cools down and converts into water droplets. Due to the difference in the amount of air pressure, the bottle shrinks.

Q4. What are the safety measures against the lightning thunder?

Answer: The safety measures that can be taken against the lightning thunder are:

(i) Go inside a building rather than staying in open

(ii) Avoid coming out of the house

(iii) Activities like washing clothes, bathing, etc. should be avoided

(iv) Do not lie down in open lands

(v) If not buildings, you can take shelter in cars or buses

(vi) Avoid standing under tall single trees

RBSE Class 8 Science Chapter 15 Long Answer Type Questions: Textbook Important Questions and Solutions

Q5. What are the reasons for lightning thunder?

Answer: With the increase in temperature, the hot air moves up and takes water vapour along with it. Then, water vapour condenses because of low temperature.

Water droplets fall down at a high speed. Hot rising air and water droplets coming down interact with each other. This produces lightning and sound. This is how the lightning thunder occurs.

Q6. Explain the reasons for the flow of air.

Answer: Earth is non-uniformly heated. The places near the equator obtain more heat of the sun than the other parts. This makes the surrounding air hot.

Cool breeze from the polar areas moves towards the equator of the earth. This inequality of heat makes the air blow from the cooler areas towards the areas of hotter zones.

During the summer season, the land becomes hot. The temperature of the ocean water precedes that of the land. The hot air that is around the land moves upwards. The area vacated by the hot air is taken by the cool sea breeze. Thus, the air starts flowing.

RBSE Class 8 Science Chapter 15 Additional Important Questions and Solutions

Q7. What are the measures that can be taken by the government during the cyclone?

Answer: The steps that can be taken by the government to prevent cyclone are:

(i) The meteorological department should issue forecasts and warnings.

(ii) Water boats, seashores, government institutions, etc. should be promptly made aware of cyclones.

(iii) Rescue Operation systems should be available to shift the public to safe areas.

Q8. What are the measures that can be taken by the public during cyclones?

Answer: The measures that can be taken by the public during cyclones are:

(i) Government warning should be taken seriously.


(ii) Driving should be avoided on the roads that are submerged in water.


(iii) Emergency services phone numbers should be noted down by the people.

(iv) Arrangements should be done by people to shift crucial goods and domestic animals to safer areas.

Q9. What are the precautions that the residents of the cyclone-prone area should take?

Answer: The precautions that the residents of the cyclone-prone area should take are:

(i) Broken electric wires and switches must not be touched.

(ii) One should help neighbours and friends in need.

(iii) Storage of drinking water should be done to be ready for the adverse situation.

Q10. What are the examples that prove that the air exerts pressure?

Answer: The examples that prove that air exerts pressure are:

– Hosting of a flag

– Rustling of leaves

– Blowing of dust

– Flying of a kite

Q11. What is a tornado? What are its other names?

Answer: Tornadoes are dark-coloured clouds in the shape of a funnel. Tornadoes seem to be originating from the sky towards the earth.

They have wind speeds less than 180 km/hr.

They are weak in nature.

Tornadoes are called a hurricane in America and typhoons in Japan.

Q12. Which ghats in India are more susceptible to cyclones?

Answer: The Eastern Ghats in India are more susceptible to cyclones.

Q13. What do we mean by natural phenomenon?

Answer: The occurrence or a phenomenon that is not artificial, is called a natural phenomenon.

The natural phenomenon can include:

  • Cyclones
  • Tornadoes
  • Fog
  • Thunder

Q14. What happens when the hot air rises up?

Answer: When the hot air rises up, a void of air is created in its earlier place. This results in decreased air pressure.

Q15. What is a breeze? Give an example.

Answer: Breeze is the moving air.

During the summer season, the land becomes hot. The temperature of the ocean water precedes that of the land. The hot air that is around the land moves upwards. The area vacated by the hot air is taken by the cool sea breeze. Thus, the air starts flowing. This moving air is called a breeze.

Q16. What is the eye of a cyclone?

Answer: There exists a calm zone in the cyclone. This zone is called the eye of the cyclone. Around the eye of the cyclone, different layers of air rotate with high speed.

Q17. What do we mean by lightning conductor?

Answer: A lightning conductor is a device that protects buildings from the lightning effects.

During the construction of the building, a long metallic rod (longer than the building) is placed in the walls of the building. Out of the two ends of the metallic rod, one is kept buried inside the ground and the other is kept outside, exposed to the air.

The metallic rod gives an easy passage for electricity to transfer to the ground.

Q18. Why do we find it difficult to enter the ball inside the bottle by blowing air into it?

Answer: The velocity of air increases at the mouth of the bottle by blowing. This results in low air pressure. The pressure inside the bottle is more in comparison to at the mouth of the bottle. Due to this, air inside the bottle pushes the ball outside the bottle.

Q19. Why do balloons come towards each other when air is blown between them?

Answer: Blowing air between balloons reduces air pressure between the balloons. High pressure on the other side of the balloons pushes them towards each other.

Thus, an increase in the velocity of air, reduces the air pressure.

Q20. How does non-uniform heating of earth make the air blow?

Answer: Heat energy that is received by earth is more on the equators. Due to this, the air in this area becomes hot. The hot air rises up and cold air from the polar areas starts to flow to take its place. The non-uniform heating in these areas causes the flow of wind.

Q21. Explain the non-uniform heating of land and water.

Answer: During summer, the areas get heated in a lesser amount of time. Land is hotter as compared to seawater. The air above the land gets heated and rises upwards.

This vacated area is replaced by cold air from the sea. Wind starts to flow due to the non-uniform heating of land and water.

Q22. Why do lightning and thundering occur?

Answer: With the increase in temperature, the hot air moves up and takes water vapour along with it. Then, water vapour condenses because of low temperature.

Water droplets fall down at a high speed. Hot rising air and water droplets coming down interact with each other. This produces lightning and sound. This is how the lightning thunder occurs.

Q23. What are the safety measures that can be taken during a thunderstorm?

Answer: During a thunderstorm, one should take the following measures:

  • Go inside a building rather than staying in open
  • Avoid coming out of the house
  • Activities like washing clothes, bathing, etc. should be avoided
  • Do not lie down in open lands
  • If not buildings, you can take shelter in cars or buses
  • Avoid standing under tall single trees

Q24. Write in detail about tornadoes.

Answer: A tornado is in the shape of a twisted funnel with high speed wind blowing. Tornadoes seem to be originating from the sky towards the earth.

Tornadoes are formed when a funnel-like pillar of cold wind sinks down from a cloud. Warm hot air moves upward, whirling up. This causes circulating winds at high speed. Tornadoes have smaller diameter in comparison to cyclones.

They have wind speeds less than 180 km/hr.

They are weak in nature.

Tornadoes are called a hurricane in America and typhoons in Japan.

Q25. What is the difference between a tornado and a cyclone?

Answer: A cyclone is an enormous and robust storm. A cyclone has a low pressure area which is surrounded by high pressure. Winds move around the centre at high speeds along with heavy rains. The diameters of the cyclones are large.

A tornado is in the shape of a twisted funnel with high speed wind blowing. Tornadoes seem to be originating from the sky towards the earth. Tornadoes are formed when a funnel-like pillar of cold wind sinks down from a cloud. Warm hot air moves upward, whirling up. This causes circulating winds at high speed. Tornadoes have smaller diameter in comparison to cyclones.

Q26. What causes a thunderstorm?

Answer: Air carrying water droplets are lifted vertically into the atmosphere due to unequal warming of the surface of the Earth. As a result of this lift, the air condenses and latent heat is released with the expansion resulting from a decrease in pressure (with the increase in height). These condensed droplets freeze and fall back to the ground along with hail and lightning.

Q27. How are the cyclones named?

Answer: Lists and names of Cyclones are maintained and updated by an international committee of the World Meteorological Organisation (WMO). The earliest lists had only names of women. In 1979 men’s names were also included. Names of men and women are used alternatively. There are six such lists and these are used in rotation.

Hence, the list used in 2020 will be used again in 2026. If the storms have wreaked havoc on a country, then the names will not be repeated again due to reasons of sensitivity. Examples are Katrina in the USA (2005), Sandy in the USA (2012), Haiyan in the Philippines (2013), Irma and Maria in the Carribean (2017).

Q28. Write an activity to create a tornado in a bottle.

Answer: Here is an activity to create a tornado in a bottle:

  • Fill about ⅔ of water into one of the bottles
  • Add food colouring or a few paper pieces (optional)
  • Now, connect both bottles using the connector
  • Place both connected bottles on a sturdy surface. The empty bottle should be on the bottom
  • The water will drip down to the lower bottle and in a few seconds, the flow stops completely
  • To make the water flow continuously to the empty bottle, move the bottles in a circular motion for a few minutes
  • After placing it on a sturdy surface, you can observe the shape of a tornado appearing on the top bottle in order to flow the water down.

Q29. Write an activity to show the effect of velocity of air on air pressure.

Answer: Take an empty bottle, make a small ball by folding a piece of paper. Keep the ball inside the bottle near the mouth. Try to insert the ball inside the bottle by blowing through the mouth of the bottle.

Repeat the same process with bottles of different sizes of the mouths.

We will see that it is difficult to enter the ball inside the bottle by blowing.

The velocity of air increases at the mouth of the bottle by blowing. This results in low air pressure. The pressure inside the bottle is more in comparison to at the mouth of the bottle. Due to this, air inside the bottle pushes the ball outside the bottle.

Q30. “Increase in the Velocity of air reduces the air pressure.” Explain with an activity.

Answer: Take two balloons of the same size and fill them both with a little amount of water.

Blow the balloons to their full size and tie them with a string. Suspend these balloons on a wooden stick and keep a distance of 10 cm between them.

Now blow air between the balloons. We will see that the balloons come towards each other.

Blowing air between balloons reduces air pressure between the balloons. High pressure on the other side of the balloons pushes them towards each other.

Thus, an increase in the velocity of air, reduces the air pressure.

Q31. What is the importance of wind for human existence.

Answer: The presence of wind is vital to human existence. Here are some of the reasons why:

  • It carries the monsoon clouds from one place to another, thus causing rains in regions away from water bodies.
  • It helps in the process of pollination and soil erosion.
  • It increases the availability of CO2 to plants for the process of photosynthesis by creating turbulence and increases transpiration.

Q32. What are the types of cyclones?

Answer: There are various types of cyclones depending on the type of prevailing low-pressure system.

  • Tropical cyclone
  • Extratropical cyclone
  • Tornadoes

Q33. Do cyclones only form on the Earth?

Answer: No, cyclones are not only present on the Earth but also spotted on other planets like Mars, Jupiter and Neptune.

The Great Red Spot is the hurricane on Jupiter which is going on from 340 years.

The Great Black Spot was spotted in the Southern Hemisphere of Neptune.

Q34. What are tropical cyclones?

Answer: Tropical cyclones are the ones that are considered to be one of the most damaging natural disasters in the world.

They begin from and escalate over hot tropical oceans.

These are fierce storms that begin from oceans in tropical areas. Then they move over to the coastal areas. This results in heavy rain, storm and intense winds.

Q35. What is an eyewall of a cyclone?

Answer: Around the eye of a cyclone is the eyewall. On the eyewall, strong winds rise in a spiral shape. They rise to a huge height reaching the tropopause.

In this region, the velocity of the wind is maximum. We can then see a torrential rain occurring here.

Q36. Give some examples of naming of cyclones.

Answer: If the storms have wreaked havoc on a country, then the names will not be repeated again due to reasons of sensitivity.

Examples are:

  • Katrina in the USA (2005)
  • Sandy in the USA (2012)
  • Haiyan in the Philippines (2013)
  • Irma and Maria in the Carribean (2017)

All the questions that have been added in the additional important questions and solutions are based on the concepts that have been taught in the RBSE textbook. The solutions are elaborate, accurate and drafted, as per the standards set forth by the board.

Stay tuned for more information about RBSE solutions and other resources.

Leave a Comment

Your email address will not be published. Required fields are marked *

BOOK

Free Class