Q1. Define vibration?
Answer: Rapid to and fro motion of an object.
Q2. How is sound produced?
Answer: Vibrating objects produce sound.
Q3. Define wave.
Answer: A wave is a disturbance produced in a medium as the particles of the medium vibrate.
Question: How do we conserve biodiversity?
Answer: Primarily two approaches are followed i.e.
1. In Situ conservation
2. Ex Situ conservation
Q1. What is the chemical symbol of lead and mercury?
Q2. Monika finds that all samples of pure water have Hydrogen and Oxygen in ratio of 1:8 by mass. Which law does the statement agree to?
Q3. 10g of silver nitrate solution is added to 10g of sodium chloride solution. What change in mass do you expect after the reaction and why?
Q1. What is the theme of the story deep waters?
Answer: Deep Water teaches its audience that it is not death; rather, everyone is afraid of dying. Otherwise, the fear would overcome us, therefore we must battle it. Past memories can also have a permanent impact on a person's thinking.
जन्म : 2 अक्टूबर 1904, मुगलसराय
निधन: 11 जनवरी 1966, ताशकंद, उज्बेकिस्तान ट्रेंडिंग
लाल बहादुर शास्त्री भारत के दूसरे प्रधानमंत्री थे। उन्होंने 1964 से 1965 तक भारत के प्रधान मंत्री के रूप में कार्य किया था। 1965 में भारत-पाक युद्ध के दौरान वह भारत के प्रधान मंत्री थे।
Radha: Hey brother, what are you doing?
Brother: Not much, just scrolling through social media.
Radha: Have you finished your homework yet?
Brother: Yeah, I finished it earlier.
The gravitational constant (G) is a fundamental physical constant that appears in Newton's law of universal gravitation. It determines the strength of the gravitational force between two objects, and it is always the same, regardless of the distance between the objects or their masses. The value of G is approximately 6.674 x 10⁻¹¹ N(m/kg)².
Chapter: Chemical Effects of Current
Directions: Read the following and answer the questions given below:
Case Study
Take out carbon rods carefully from two discarded cells. Clean their metal caps with sandpaper. Wrap copper wires around the metal caps of the carton rods to form electrodes and join them to a battery, Pour a cupful of water into a glass/plastic bowl. Add a teaspoonful of salt or a few drops of lemon juice to water to make it more conducting. Now immerse the electrodes in this solution. Make sure that the metal caps of the carbon rods are outside the water. Wait for 3-4 minutes, Observe the electrodes carefully.
CBSE Class 8 - Physics - Sound - Case Study Based Question
Q1. Read the following and answer the questions given below:
Sound is a form of energy that is produced when air molecules vibrate in a particular pattern called waves. Hence, the sound is a wave. Sound is produced by vibrating objects. Vibration can be described as to and fro motion of an objects. Sound cannot be produced without any vibrations. Sound always requires a medium to travel from the source of its production to the receiver end. Speed of the sound is maximum in solids and minimum in gases.
Very Short Answer Type Questions
1. Name three useful products of coal.
2. Which product of coal is used as a reducing agent in the extraction of metals?
3. Name the process by which plant material (or vegetation) buried deep under the earth was slowly converted into coal.
4. Name the product of coal, which is a thick black liquid with an unpleasant smell.
Various steps involved in agriculture are collectively known as agricultural practices, which include:
1. At present about 118 elements are known.
2. Elements can be divided into two main groups: metals and non-metals.
3. Elements which form positive ions by losing electrons are called metals. Thus, metals are the elements which have the tendency to lose electrons.
Children's Day is observed in India every year on November 14. It falls on a Monday this year. Because Pandit Jawaharlal Nehru, often known as Chacha Nehru, had a special affection for children, the day is observed on his birthday. He was India's first prime minister and held the view that youth are the nation's future and have the potential to influence its future development. Children dress colorfully, perform special acts, and schools organise cultural events to honour Jawaharlal Nehru's teachings and legacies on Children's Day.
Without children, there would be no joy, laughter, or love in the world. Children are therefore God's most precious creation, and we should do everything in our power to safeguard, educate, and cherish them. Greetings on Children's Day!
