Some Natural Phenomena – Short Answer Type Questions
CBSE Class 8 Science – Chapter 15: Some Natural Phenomena
Aligned with CBSE Board Examination Pattern:
- Strictly based on the latest NCERT textbook and syllabus.
- Short answer questions with clear, exam-focused solutions.
- Ideal for school tests, annual exams, and CBSE Class 8 board exam standard.
- Topic-wise coverage for quick revision and concept clarity.
Short Answer Type Questions – Chapter 15: Some Natural Phenomena
These 50 Short Answer Type Questions with easy-to-understand answers are designed strictly as per the NCERT syllabus. They cover all important topics of Chapter 15 – Some Natural Phenomena and are ideal for CBSE Class 8 exam preparation and quick revision.
1. Electric Charge and Static Electricity
Q1. What is meant by electric charge? Name its two types.
Ans. Electric charge is a basic property of matter due to which substances exert electrical forces on each other.
The two types of electric charges are positive charge and negative charge.
Q2. When is an object said to be electrically neutral?
Ans. An object is electrically neutral when it has an equal number of positive charges (protons) and negative charges (electrons),
so the net charge on it is zero.
Q3. Define static electricity with one simple example.
Ans. The electric charge that remains at rest on the surface of an object is called static electricity.
Example: A plastic scale rubbed with dry hair attracts small pieces of paper due to static charge.
Q4. How does an object get positively charged?
Ans. An object becomes positively charged when it loses electrons.
Loss of negatively charged electrons leaves an excess of positive charge on the object.
Q5. How does an object get negatively charged?
Ans. An object becomes negatively charged when it gains extra electrons.
The excess electrons make the object carry a net negative charge.
Q6. What is meant by “charging by rubbing”?
Ans. When two objects are rubbed against each other, electrons are transferred from one object to the other.
As a result, one object becomes positively charged and the other becomes negatively charged.
This is called charging by rubbing or frictional charging.
Q7. Why are dry conditions more suitable for observing static electricity?
Ans. In dry weather, moisture content in air is low, so electric charges do not leak away easily.
Therefore, static charges remain on objects for a longer time and their effects (like attraction of paper bits) are more easily observed.
Q8. Why does a charged body eventually lose its charge when left in open air?
Ans. Air contains moisture and dust particles which allow charges to leak away slowly from the charged body to the surroundings.
This gradual leakage of charge makes the body neutral again.
2. Interaction of Charges and Methods of Charging
Q9. State the basic rule of interaction between like and unlike charges.
Ans. The basic rule is: like charges repel each other and unlike charges attract each other.
This rule is the foundation of electrostatic interactions.
Q10. Give one activity to show that like charges repel each other.
Ans. Charge two inflated balloons by rubbing them with a woollen cloth. When brought close,
both balloons move away from each other, showing that like charges repel.
Q11. Give one activity to show that unlike charges attract each other.
Ans. Rub a glass rod with silk to make it positively charged and a plastic rod with wool to make it negatively charged.
When the rods are brought close, they attract each other, showing that unlike charges attract.
Q12. Can a charged body attract an uncharged body? Explain briefly.
Ans. Yes, a charged body can attract an uncharged body. When a charged object is brought near a neutral object,
charges inside the neutral object get rearranged (induced). The unlike charges come closer and attraction is observed.
Q13. Distinguish between conductors and insulators with examples.
Ans. Conductors allow electric charges to move freely through them. Example: copper, aluminium.
Insulators do not allow charges to move freely. Example: plastic, rubber, glass.
Q14. What is earthing? Why is it useful?
Ans. Earthing is the process of connecting a body to the Earth through a metal wire to transfer excess charge safely.
It prevents electric shocks and protects electrical appliances and buildings from damage.
Q15. Why should we not touch electrical appliances with wet hands?
Ans. Water is a good conductor of electricity. Wet hands decrease our body’s resistance and allow current to pass easily,
increasing the risk of electric shock, so this must be avoided.
3. Electroscope and Detection of Charge
Q16. What is an electroscope? State its use.
Ans. An electroscope is a simple device used to detect the presence of electric charge on an object.
It shows whether an object is charged or not by the divergence of its metal leaves.
Q17. Describe the basic construction of a simple electroscope.
Ans. A simple electroscope consists of a metal rod passing through a cork or rubber stopper into a glass jar.
Two thin metal leaves are attached to the lower end of the rod, while the upper end has a metal disc or knob.
Q18. What happens to the leaves of an electroscope when a charged body touches its metal disc?
Ans. The charge from the body spreads to the metal leaves.
Both leaves get the same type of charge, so they repel each other and move apart, indicating that the body was charged.
Q19. Why do the leaves of an electroscope collapse when we touch the metal disc with our hand?
Ans. Our body provides a path for the charges to flow to the Earth (earthing).
When the charge leaks away through our body, the leaves lose their charge and come back together.
Q20. Can an electroscope tell whether the charge is positive or negative? Explain.
Ans. A simple electroscope can tell only whether an object is charged or not.
To identify the type of charge, we need to compare it with a known charged body using additional steps, which is beyond elementary use.
Q21. How can an electroscope be used to show that charge can be transferred from one body to another?
Ans. First, charge the electroscope so its leaves diverge. Then touch another neutral object to the electroscope disc.
If the leaves partially or completely collapse, it shows that some charge has been transferred to the other object.
4. Lightning – Cause and Formation
Q22. What is lightning? How is it related to static electricity?
Ans. Lightning is a sudden, bright flash of light in the sky followed by thunder, caused by a massive electric discharge
between clouds or between a cloud and the Earth. It is a large-scale example of discharge of static electricity in nature.
Q23. How do clouds become electrically charged?
Ans. In stormy weather, fast winds cause water droplets and ice particles in clouds to rub against each other.
This rubbing (friction) transfers electrons and causes separation of charges, making different parts of the cloud positively or negatively charged.
Q24. Describe briefly how lightning is produced.
Ans. When the charge difference between clouds, or between a cloud and the Earth, becomes very large,
air cannot resist the flow of charges. A sudden discharge of electricity takes place through the air,
producing a bright flash (lightning) and sound (thunder).
Q25. Why do we sometimes see lightning first and hear thunder later?
Ans. This is because light travels much faster than sound.
The flash of lightning reaches our eyes almost instantly, while sound of thunder takes more time to reach our ears.
Q26. What causes the loud sound during lightning?
Ans. The electric discharge of lightning heats the surrounding air suddenly.
This hot air expands rapidly and then contracts, creating shock waves which we hear as thunder.
Q27. Why is lightning considered dangerous for living beings?
Ans. Lightning carries a very high amount of electric energy.
It can cause severe burns, heart failure, or even death in living beings and may also start fires or damage buildings and trees.
Q28. What is the role of air in the formation of lightning?
Ans. Normally, air acts as an insulator and prevents charges from flowing.
But when the electric field becomes very strong, the air breaks down and becomes a conductor, allowing a huge current to flow as lightning.
5. Lightning Safety and Protection
Q29. List any three safety measures to be followed indoors during a thunderstorm.
Ans. (i) Stay away from windows and doors.
(ii) Avoid using wired telephones, televisions, and other electrical appliances.
(iii) Do not touch metal pipes or taps and avoid taking a shower during lightning.
Q30. What precautions should be taken if you are caught outside in an open field during a thunderstorm?
Ans. Move to a low-lying area, squat down with your feet close together, keep your head low, and hands on your knees.
Avoid standing under isolated trees, tall poles, or near metal objects.
Q31. Why is it unsafe to stand under a single tall tree during lightning?
Ans. A single tall tree acts as a good conductor and is likely to be struck by lightning.
The electric current may pass through the tree and the person standing under it, causing serious injury or death.
Q32. Is it safe to sit inside a car during a thunderstorm? Give reason.
Ans. Yes, it is generally safe to sit inside a car with windows closed.
The metal body of the car conducts the electric charge around the outside and to the ground, protecting people inside (Faraday cage effect).
Q33. What is a lightning conductor and how does it protect a building?
Ans. A lightning conductor is a metal rod fixed at the top of a building and connected to a metal strip leading into the ground.
When lightning strikes, the conductor provides a safe path for the electric charge to flow into the Earth,
preventing damage to the building.
Q34. Why are lightning conductors usually made of metals like copper?
Ans. Metals like copper are good conductors of electricity and are also durable and corrosion-resistant.
They allow lightning charges to flow quickly and safely to the ground without heating up excessively.
Q35. Who first explained the connection between lightning and electric spark on Earth?
Ans. Benjamin Franklin, an American scientist, showed that lightning is an electric discharge similar to the spark
produced on Earth, using his famous kite experiment.
Q36. Why should we unplug electrical appliances during a thunderstorm?
Ans. Lightning can cause sudden surges in the power supply which may damage electrical appliances.
Unplugging them prevents damage and reduces the risk of electric shock and fire.
6. Earthquakes – Causes and Important Terms
Q37. What is an earthquake?
Ans. An earthquake is a sudden shaking or trembling of the Earth’s surface caused by a disturbance deep inside the Earth,
usually due to the movement of tectonic plates.
Q38. What is meant by tectonic plates?
Ans. The Earth’s crust is broken into large, rigid pieces called tectonic plates.
These plates float on the semi-molten layer below and are constantly moving very slowly relative to each other.
Q39. Distinguish between focus and epicentre of an earthquake.
Ans. The focus is the point inside the Earth where the earthquake originates.
The epicentre is the point on the Earth’s surface directly above the focus.
Shaking is usually strongest near the epicentre.
Q40. What are seismic waves?
Ans. The waves produced by an earthquake that travel through the Earth and cause the ground to shake are called seismic waves.
They are responsible for the destruction caused during an earthquake.
Q41. Name the instrument used to record earthquakes. What does it record?
Ans. A seismograph is used to record earthquakes.
It records the time of occurrence, duration, and the intensity of seismic waves on a paper or digital screen.
Q42. On which scale is the magnitude of an earthquake measured?
Ans. The magnitude (strength) of an earthquake is measured on the Richter scale.
Higher values on this scale indicate stronger and more destructive earthquakes.
7. Effects and Safety Measures During Earthquakes
Q43. Mention any three harmful effects of earthquakes.
Ans. (i) Collapse of buildings, bridges, and roads.
(ii) Loss of human and animal lives.
(iii) Damage to water pipelines, gas lines, and power lines, leading to fires and floods.
Q44. What should you do if an earthquake occurs while you are inside a building?
Ans. Stay calm, take shelter under a strong table or bed, protect your head, stay away from windows and heavy furniture,
and do not use lifts during the tremors.
Q45. What safety measures should be taken if you are outdoors during an earthquake?
Ans. Move to an open area away from buildings, trees, electric poles, and bridges.
Do not stand near walls or flyovers and stay away from the seashore in case of possible tsunamis after strong earthquakes.
Q46. Why is it safer to live in houses made of wood or light materials in earthquake-prone areas?
Ans. Wooden or light structures are more flexible and less likely to collapse completely during an earthquake.
Even if they are damaged, they cause less harm compared to heavy concrete buildings.
Q47. Can scientists predict earthquakes accurately? Explain briefly.
Ans. No, earthquakes cannot be predicted accurately in terms of time and place.
Scientists can only identify earthquake-prone zones and design better safety measures, but exact prediction is still not possible.
8. Mixed Conceptual and Application-Based Questions
Q48. Why do we see sparks when we take off a woollen sweater in a dark room?
Ans. When a woollen sweater rubs against our body or clothes, charge is produced due to friction.
When these charges suddenly discharge through air, tiny sparks are produced, which can be seen in a dark room.
Q49. A child receives an electric shock from a metal object during a thunderstorm. What might have gone wrong and how could it be avoided?
Ans. The metal object might have become charged due to lightning-induced electrical surges.
It could be avoided by staying away from metal fences, poles, and electrical appliances during a thunderstorm and by proper earthing.
Q50. How does learning about natural phenomena like lightning and earthquakes help us in daily life?
Ans. Understanding these phenomena helps us follow correct safety measures, design safer houses and buildings,
reduce loss of life and property, and stay calm and prepared during such natural events.
Exam Note: These Short Answer Type Questions for Chapter 15 – Some Natural Phenomena are prepared
strictly as per NCERT Class 8 Science syllabus. Practice writing these answers in your own words to improve speed, accuracy,
and score better in CBSE Class 8 examinations.