Topics
Crop Production and Management
- Crop and Its Types
- Soil Formation and Preparation for Agriculture
- Agricultural Implements
- Manuring (Biomanuring)
- Fertilizers
- Methods to Replenish Nutrients in Your Soil
- Improved methods of agriculture
- Food Security
- Weeding
- Harvesting of Crops
- Storage of Food Grains
- Animal Products used as Food
Microorganisms: Friend and Foe
Synthetic Fibres and Plastics
- Fibre
- Fabrics
- Man-made Fibre: Synthetic Fibres
- Rayon
- Nylon
- Dacron, Terylene, Terene
- Man-made Fibre: Plastics
- Biodegradable Plastics
- Harmful Effects of Plastics
- Recycling of Plastic
Coal and Petroleum
- Energy Resources > Conventional energy resources or non-renewable energy resources
- Carbon: A Versatile Element
- Special Features of Carbon
- Non-crystalline/Amorphous Forms: Coal
- Extraction of Coal
- Non-crystalline/Amorphous Forms: Coke
- Petroleum
- Refining of Crude Petroleum
- Conventional Sources of Energy > Natural Gas
- Some Natural Resources Are Limited
Materials: Metals and Non-metals
Combustion and Flame
- Chemical Properties of Carbon Compounds > Combustion
- Precautions and Safety Measures
- Types of Combustion
- Flame
- Fuel
- Types of Fuel
- Fuel Efficiency
Conservation of Plants and Animals
- Deforestation and Its Causes
- Consequences of Deforestation
- Conservation of Forests
- Conservation of Wildlife
- Endemic Species
- Migration
- Recycling of Paper
- Reforestation
Reproduction in Animal
- Fertilization in Human
- Embryo Formation in Viviparous and Oviparous Animals - Young Ones to Adults
Reaching the Age of Adolescence
- Secondary Sex Characteristics
- Role of Hormones in Initiating Reproductive Function
- Reproductive Phase of Life in Humans
- Hormones Other than Sex Hormones
- Role of Hormones in Completing the Life History of Insects and Frogs
- Nutritional Needs of Adolescents
- Personal Hygiene for Adolescence
Cell - Structure and Functions
Force and Pressure
- Force
- Force - Push or Pull
- Forces Are Due to an Interaction
- Exploring Forces
- A Force Can Change the State of Motion
- Force Can Change the Shape of an Object
- Effect of Force
- Types of Forces>Contact and Non-Contact Forces
- Thrust and Pressure
- Pressure of liquid
- Factors Affecting Liquid Pressure
- Atmospheric Pressure
Friction
- Force of Friction
- Factors Affecting Friction
- Friction - A Necessary Evil
- Effects of Friction
- Increasing and Reducing Friction
- Fluid Friction
Sound
Chemical Effects of Electric Current
- Conductor of Electricity: Liquid
- Electricity
- Chemical Effects of Electric Current
- Electrical Conduction in Solids
Some Natural Phenomena
- Lightning and Lightning Safety
- Force of Friction
- Electric Charge
- Types of Charges and Their Interaction
- Transfer of Charges
- Electroscope
- Lightning and Lightning Safety
- Earthquake
- Protection Against Earthquakes
Light
- Climatic Factors > Light
- Reflection of Light
- Terms Used in Reflection of Light
- Law of Reflection of Light
- Types of Reflection
- Multiple Reflections
- Prism
- Dispersion of Light
- The Human Eye
- Care of the Eyes
- Visual Impairment and Braille System
Star and Solar System
Pollution of Air and Water
- Pollution
- Case Study: The Taj Mahal
- Green House Effect
- Preventive Measures of Green House Effect
- Preventive Measures of Global Warming
- Case Study: Ganga Pollution and Ganga Action Plan
- Potable Water
- Purification of Water
- Introduction
- Causes of Lightning
- Precautions to Stay Safe from Lightning
Maharashtra State Board: Class 7
Introduction:
Lightning is caused by the movement of electric charges within clouds or between a cloud and the ground. This generates a high-temperature flash, hotter than the sun. Only 5% of lightning strikes the ground, while most remain in the sky. When lightning occurs, it heats the air and causes it to expand suddenly, creating the crashing sound of thunder.
Maharashtra State Board: Class 7
Causes of Lightning:
- Electric charges build up inside a cloud.
- Lightning occurs within one cloud, between clouds, or between a cloud and the ground.
- The high temperature generated by lightning causes air to expand and thunder to occur.
Maharashtra State Board: Class 7
Precautions to Stay Safe from Lightning:
- Avoid open areas or standing under a tree.
- Do not climb trees or go to high places.
- Stay away from poles, towers, or wired fences.
- If you are on a bike, tractor, or boat, get off and find shelter.
- Do not gather in one group; keep 15 feet distance between people.
- Avoid using electrical appliances, mobiles, or telephones during a storm.
- Stand on dry wood, leaves, or plastic to stay insulated.
- Swimmers and fishermen should get out of the water immediately.
- The safest place is a pucca (solid) house.
- Install a lightning conductor on tall buildings or houses for safety.
