NCERT Solutions for Class 8 Chapter 15
Learning about the natural world using observation and experimentation is known as science. Scientists gain knowledge of the natural world by conducting studies that provide evidence that helps answer their questions. Experiments or observations of the natural environment are a part of the research. Scientists conduct research using different scientific methods. Science is divided into several branches, each of which is further subdivided into more focused research fields.
NCERT Class 8 Science Chapter 15 is Some Natural Phenomenon. Natural phenomena such as Lightning and Earthquakes are discussed in class 8 science chapter 15 along with precautions that should be taken to reduce the damage caused by these events. In addition, it features a discussion of many other natural wonders. For example, it covers Lightning’s cause, effects, attributes, magnitude, and electroscope operations.
NCERT Solutions does wonders for students who are preparing for their examinations. Extramarks has come up with Class 8 Science Chapter 15 Solutions. These NCERT Solutions of Some Natural Phenomena Class 8 are made exclusively by the experts of Extramarks after thorough research. They try to meet all the requirements of the students.
Extramarks can be a one-stop solution for all students’ problems. Apart from NCERT Solutions for Class 8 Science Chapter 15- Some Natural Phenomenon, NCERT Solutions of other subjects, Additional Questions, Sample Papers, Revision Notes, CBSE past years’ question papers, and a lot more can be found on the Extramarks website.
Key Topics Covered in NCERT Solutions for Class 8 Science Chapter 15
The key topics covered in NCERT SOLUTIONS are enlisted below to make it easier for students.
| Introduction to Natural Phenomenon |
| Static Charges |
| Lightning |
| Earthquakes |
Let us look at Extramarks’ in-depth information on each subtopic in NCERT Solutions for Class 8 Science Chapter 15- Some Natural Phenomena.
Introduction to Natural Phenomenon
Natural phenomena refers to any disaster or physical process that occurs naturally.
Lightning and earthquakes are two natural disasters that NCERT Solutions for Class 8 Science Chapter 15 discusses.
Static Charges
Any atom, we know, is made up of subatomic particles like electrons, protons, and neutrons. These particles have one thing in common: they have electrical charges. For example, protons have a positive charge, while electrons have a negative charge. Although we know that atoms have a balanced charge, this charge can easily fall out of order. If the proportion of positive and negative charges in an item is balanced, it is termed as electrically neutral.
Methods of Charging:
- Rubbing which causes friction or induction are the two processes that could charge a body.
- Static charges are the electrical charges created by rubbing.
Charging by Rubbing
Another important aspect that Extramarks NCERT Solutions for Class 8 Science Chapter 15 explains is Charging by rubbing. When we rub two items together, electrons are transferred between them, and the objects become charged. For example, when we brush a rubber balloon against animal hair, the rubber balloon draws electrons from the animal fur. As a result, rubber has an overabundance of electrons, whereas fur has an electron deficit. Similarly, we may charge a plastic comb by rubbing it across dry hair.
Charged Objects
Charged objects are items that carry a charge through rubbing or other processes.
Transfer of Charges
Using excellent conductors (metals), charges can be transferred from one conducting substance to another using excellent conductors (metals). The migration of an electron from one atom to another causes charge transfer, states NCERT Solutions for Class 8 Science Chapter 15.
Electroscope
An electroscope is a scientific instrument that can detect the presence of an electric charge on a person’s body. The first electroscope with a pivoting needle, dubbed versorium, was created in 1600 by the British physician William Gilbert.
An electroscope on top is made up of a metal detector knob which is then connected to a pair of metal leaves hanging from the bottom of the connecting rod.
The charge is detected using an electroscope using the Coulomb electrostatic force, which causes the test charge to move. Because the electric charge of an item is equal to its capacitance, an electroscope may be used as a primitive voltmeter. The device that measures the charge quantitatively is called an electrometer.
The passage of electrons into or out of the leaves is how an electroscope responds to the presence of a charge. The leaves split in both circumstances. It’s vital to remember that the electroscope can’t tell if the charged object is positive or negative; it simply looks for an electrical charge.
Discharged Objects
Discharged objects are those that have lost their charge due to a transfer.
Earthing
Earthing is transferring charges from a charged item to the Earth.
Lightning
Extramarks NCERT Solutions for Class 8 Science Chapter 15 explains the story of Lightning and its aspects in the following section.
Air currents rise upwards during thunderstorms, whereas water droplets fall downwards. This results in charge separation between clouds and the ground.
When the magnitude of charges grows, air (generally a poor conductor) begins to conduct and permits electricity to flow. Lightning is named from the dazzling streaks of light and sound that accompanies the charge movement.
Electric Discharge
An electric discharge is the movement of charge from cloud to cloud or cloud to ground resulting in the separation of positive and negative charges.
Lightning safety steps to follow
Outside the house:
- Find a secure spot or take refuge under a small tree.
- Stay inside a car or vehicle with the doors and windows closed.
- Metal poles should be avoided.
- Avoid lying on the ground. Crouch with your head between your hands instead.
Inside the house:
- Contact with telephone and electrical cables should be avoided.
- Bathe sparingly.
- Disconnect all electrical appliances.
Lightning Conductors
Lightning conductors help in the protection of structures from Lightning. They are made out of a taller-than-the-building metal rod inserted into the walls during construction. They extend to the ground and serve as a direct path for electric discharge following lightning strikes.
The above section of Extramarks NCERT Solutions for Class 8 Science Chapter 15 explains the story of Lightning and its various aspects. In addition, refer to the Extramarks website to gain more information or study material for all classes.
Earthquakes
Extramarks NCERT Solutions for Class 8 Science Chapter 15 briefly discusses Earthquakes in the following section.
An earthquake is a brief shaking of the ground caused by a movement deep under the surface of the Earth. The four layers that make up the Earth on the inside are called the crust, mantle, outer core, and inner core. The crust comprises many different layers that protect the inner layers. It is fragmented into smaller plates. These plates are constantly moving. Each time they clash or travel above/below each other, they cause a disturbance in the crust. This contact causes an earthquake.
What causes an Earthquake?
Earthquakes get triggered due to tectonic shifts in the Earth’s crust. Orogeny occurs when the tectonic plates glide over one another, resulting in tremors and volcanic eruptions. Vibrations spread in all directions due to these disruptions. As the plates move closer together, tension builds up, broken by shock waves, which release the stored energy.
Movement of Plates
Each portion of the Earth’s crust is referred to as a plate. These plates are continually moving and can collide under one another, resulting in a surface earthquake.
Fault or Seismic Zones
On the Earth’s crust, plate boundaries are weak zones where earthquakes are most prone to occur. They’re called Seismic or fault zones.
Measuring the strength of the Earthquake
- An earthquake’s strength is measured in magnitude on a scale. The Richter Scale is the name for this scale.
- A devastating earthquake is one with a Richter magnitude greater than 7.
- This is not a linear scale. i.e. a two-fold increase in destructive energy equals 1000 times more destructive energy.
Seismic Waves
Seismic waves are created when tremors deep within the ground cause waves.
Seismograph
A device that detects and records the intensity of seismic waves is called a seismograph. When an earthquake occurs, it contains a metal rod or a pendulum that can vibrate. A pen is linked to the metal rod, which records the waves on paper. Scientists examine the waves and then generate an earthquake map. This also aids in determining the magnitude of the Earthquake.
How do you stay safe from an Earthquake?
Outdoors:
- Find an area that is free of overhead wires and structures.
- If you’re in a car, pull over to a safe area and stay inside until the tremors end.
Indoors:
- Stay beneath a table until the shaking stops.
- Stay away from tall, hefty items.
Structural Measures:
- Build mud buildings with light roofs in seismically active locations to reduce damage.
- Fix shelves and cupboards to the walls.
- Some structures catch fire during earthquakes, necessitating suitable firefighting apparatus.
Extramarks NCERT Solutions for Class 8 Science Chapter 15 has discussed the Earthquake and its impacts in the above section. Extramarks provides material that is ready to solve all your doubts and queries. Refer to Extramarks today.
NCERT Solutions for Class 8 Science Chapter 15 Exercise and Solutions
The best way to comprehend all of the concepts of each chapter is to study the NCERT Solutions for that chapter. As a result, Extramarks provides NCERT Solutions for each chapter. Subject experts prepare these Solutions to fulfill all of the needs of the students. Click on the below links to view NCERT Solutions for Class 8 Science Chapter 15:
Class 8 Science Chapter 15: Very Short Answer Type Questions
Class 8 Science Chapter 15: Short Answer Type Questions
Class 8 Science Chapter 15: Long Answer Type Questions
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By getting access to NCERT Solutions for Class 8 Science Chapter 15- Some Natural Phenomena, students can easily understand all the chapter’s concepts by going through intensive answers to the NCERT questions of this chapter
NCERT Solutions Class 8 Science Chapter-wise List
Key Features of NCERT Solutions for Class 8 Science Chapter 15
As mentioned earlier, Extramarks NCERT Solutions have proven to be a boon for students. They have been prepared to meet all the requirements of the students. Moreover, experts curate NCERT Solutions at Extramarks to assist students in their upcoming examinations. Let us give you some reasons why should you choose us:
- These solutions have been made in simple language to make it convenient for the students to grasp the NCERT questions and answers.
- The subject experts have prepared these solutions at Extramarks after good research.
- These answers are simple and comprehensive, covering all of the chapter’s concepts.