•  Ploughs are used for tilling the soil, adding manure and fertilisers and for scraping the soil.
•  Leveller is used to level the soil to prevent it from soil erosion. A plank is used to break the crumbs into fine soil. 
•  Hoe was used for tilling in olden days, but these days we use it only to remove weeds.
•  Cultivator pulled by a tractor, is also used to break the soil.
•  Traditional seed drill contains a funnel-shaped container through which seeds pass and get placed into the soil.
•  Modern seed drills sow seeds at a proper depth and distance, and cover them with a layer of soil.

When the surface area is doubled, keeping the force constant, the pressure will decrease. b] When the force is doubled, keeping the area constant, pressure will increase.

Plants do need food for their survival and they would not wait or depend on others to provide them with food. There is a particular mechanism in plants with which they prepare their food. This mechanism is known as Photosynthesis.
Photosynthesis is a biological process used by plants to prepare food with the help of sunlight water and carbon dioxide. The name photosynthesis is derived from the Greek word ”Photo” meaning light and “Synthesis” meaning connecting together. This means combining together with the help of light energy.

Leaves are made up of small cells which have a tiny structure known as chloroplasts. Each chloroplast contains a green colored pigment  called chlorophyll. Light energy is absorbed by chlorophyll molecules whereas carbon dioxide (CO₂) and oxygen (O₂) enter through the tiny pores of stomata located in the epidermis of leaves.

Oxygen is considered one of the most important by-products of this process on which most of the living organism depend upon. Glucose/Sugar is a form of carbohydrates that is processed during the process of photosynthesis. It is commonly used by green plants in the form of an energy source to produce leaves, fruits, flowers, and seeds. The glucose molecules then combine with each other to develop more complex carbohydrates like cellulose and starch. The cellulose is considered as the structural material that is used in plant cell walls. The overall reaction of photosynthesis process is:

Plants do need food for their survival and they would not wait or depend on others to provide them with food. There is a particular mechanism in plants with which they prepare their food. This mechanism is known as Photosynthesis.
Photosynthesis is a biological process used by plants to prepare food with the help of sunlight water and carbon dioxide. The name photosynthesis is derived from the Greek word ”Photo” meaning light and “Synthesis” meaning connecting together. This means combining together with the help of light energy.

Crop is a plant that is grown on a large scale commercially. Pulses, Cereals, Oil seeds, Vegetables & fruits are different types of crop.

There are 2 cropping patterns based on India’s climatic conditions:

• Kharif crops

Crops grown in rainy season are termed as Kharif crops. Examples: Maize, soyabean, sugarcane.

• Rabi crops

Crops grown in winter season are termed as Kharif crops. Examples: Wheat, Gram, Pea

Cation:  A positively charged particle in a molecule is called cation.
Example: Na⁺, Ca⁺².
 
Anion:  An anion is a negatively charged particle in a molecule.
Example: F^-, Cl^-.

The polymer of cotton is cellulose which is obtained from various plants .

An electrolytic cell is a device which converts electric energy into chemical energy ..anode is the positive electrode and it gets its name as anode because anions migrate towards it.
Cathode is the negative electrode and its get its name as cathode because cations migrate towards its ..
an example is the electrolysis of NaCI
When the current is switched on the ions migrate towards the respective electrodes
at anode : Cl^- undergoes oxidation 2Cl^- → Cl₂ + 2e^-

at cathode : Na⁺ ions undergo reduction Na⁺ +e^- → Na

net cell reaction:

2NaCl → 2Na + Cl₂

Agriculture
It is the systematic use of basic practices to grow the crops which provide food.
Agricultural practices are a collection of principles that are applied as on-farm production and the post-production processes to produce safe and healthy food.

Most of the stars you see in the night sky with your naked eye are individual stars inside our own galaxy. It takes telescopes to see the stars outside our galaxy or even to see other galaxies. The stars in our galaxy are all orbiting in a nearly circular path around the center of the galaxy. They do this because the immense combined mass of the galaxy, most if it near the center, creates immense gravity that pulls all the stars in our galaxy into circular orbits. In addition, each star in the galaxy has a small random motion relative to the overall galactic rotation. The same concepts apply to stars in other galaxies. Each star orbits its galaxy's center and has a slight random motion on top of this. Each star does not careen randomly about like a drunkard. Rather, each star travels on a smooth, nearly-straight trajectory as dictated by its own momentum and the local gravitational field. But when comparing the motion of many stars in a galaxy and subtracting out their galactic rotation, you end up with a random distribution. The reason for this is simply the randomness of the materials from which the stars formed, and the tendency of objects to drift under their own inertia in nearly the same path for eons in the near-vacuum of space.

We get honey from honeybees. A honeybee visits flowers and gathers some of its nectar. It collects nectar from many flowers and then prepares honey from it. Honey is sweet and is consumed by humans. Colonies of honey bees called as hives are maintained and reared to collect honey and other products like wax.This process is called Beekeeping or apiculture.

The process of transferring the seedlings from the nursery to the fields is called the transplantation. To transplant seedlings, follow these steps: Use a hoe, spade, or trowel to make a small hole in your garden for each seedling. The hole should be deep enough so the transplant is at the same depth in the ground as it was in the pot (except for tomatoes).

• An electric fuse is a safety device used to limit the current in an electric circuit. The use of a fuse is to safeguard the electric circuit and the electric appliances connected in the electric circuit from being damaged.
•  A fuse is a short piece of wire made up of a material of high resistivity and of low melting point, So that it may easily melt due to overheating due to the excessive flow of electric current.
• The thickness of the fuse wire is different in different fuses depending on the amount of current which is permitted to flow through them. Generally an alloy of tin and lead is used as the material of the fuse wire as it has high resistivity and low melting point.
• Usually the fuse wire is a thin wire to be the resistance of the fuse wire is much more than that of the live wire.

Petroleum is also known as Black Gold -

 because when crude oil is extracted from the land it is black in color. People call it gold because of its oils and value . It is very difficult to find. So it is called Black Gold.

The same kind of plants grown and cultivated on a large scale at a place is called  crop.

We can conserve the forests.

• Regulated and planned deforestation
• Reforestation
• Control on forest fires
• Proper utilization of forest and forest products
• Forest management and sustainable growth.

The no. of times heart beats in aminute is called pulse rate.  To get an accurate reading, place your finger on an artery and count the pulses upto 60 seconds. Generally, a lower pulse or a heartbeat indicates that a person is physically fit and the heart muscles are in a good condition.

An unexpected natural or man-made catastrophe of substantial extent causing significant physical damage or destruction, loss of life or sometimes permanent change to the natural environment.

The pitch of a sound is our ear’s response to the frequency of sound. Whereas loudness depends on the energy of the wave. In general, the pitch is the reason behind the difference in voice quality of different individuals.
The pitch of a sound depends on the frequency while loudness of a sound depends on the amplitude of sound waves. Amazingly, many musicians, who have been trained are capable of detecting a difference in frequency between two separate sounds that is as little as 2 Hz.

A lubricant is a substance introduced between two moving surfaces to reduce friction between them. For example grease is applied between the moving parts of a machine.