Question

Answer the following questions:
Q.1 Why is weeding necessary?
Q.2. What kind of seeds to be required to get good crops ?
Q.3 Difference between natural fibres and synthetic fibres.
Q.4. Write an activity to demonstrate that liquid pressure varies with depth.
Q.5. What are the characteristics of Electrostatic force.
Q.6. Write the characteristics of Magnetic force.
Q.7. What are the advantages of synthetic fibres over natural fibres?
Q.8. What are the uses of plastics in our life?
Q.9. Ram has a cotton shirt and a shirt made from synthetic material. Which shirt is
suitable summers ? Explain.
Q.10 How Rayon is obtained ?​

Answer 1

Answer:

1) Weeding is an important control method practiced in many crops. The removal of weeds is useful because these unwanted plants compete with the crop for space, water and nutrients. ... Weeding also helps to loosen the soil. Water can infiltrate more rapidly and roots of the cultivated plants can develop in a better way.

Answer 2

Explanation:

1. Weeding is an important control method practiced in many crops. The removal of weeds is useful because these unwanted plants compete with the crop for space, water and nutrients. ... Weeding also helps to loosen the soil. Water can infiltrate more rapidly and roots of the cultivated plants can develop in a better way.
2. For farmers, the decision on what seeds to plant often occur in the fall, while harvesting the previous years crop. Every fall, grain farmers across the Midwest and beyond harvest their crops and compare which soybean or wheat varieties or corn hybrids were the best throughout the year and of course which have the best resulting yield. On average if a farmer is pleased with a certain variety they will purchase and replant it again the following year, if not, then they look for something new...
4. First the farmer must determine which Production method best fits their needs, This will determine which seed category he/she will purchase from, and yes contrary to what the Natural News’s of the internet say, there are countless seed options to choose from for each Production Method. If you need proof, just ask any farmer...
6. Natural fabrics, like merino wool, cotton, cashmere, and silk, are made of fibers that are produced by animals and plants. Synthetic fabrics, like polyester, nylon and acrylic, are "man-made" fibers that are created in laboratories.
7. Drill three equal small holes in its side at different heights from bottom. Fill the can with water qnd observe. ... This shows that the pressure if water in the can is greatest near the lowest hole and least near the uppetmost hole. Thus the pressure due to liquid increases with depth from the surface of the liquid.
8. According to Coulomb, the electric force for charges at rest has the following properties: Like charges repel each other; unlike charges attract. Thus, two negative charges repel one another, while a positive charge attracts a negative charge. The attraction or repulsion acts along the line between the two charges.
9. Characteristics of magnetic lines of force: The magnetic field at any given point is specified by both a direction and magnitude. ... The magnetic lines of force are uniform and strong at the center or inside of the conductor and they diverge as they move away from the conductor and as the distance increases.
10. Synthetic fibre are cheap, they do not shrink, they last longer than natural fibres, they dry quickly, they need little or no ironing, they are resistant to chemicals. Synthetic fibres are very strong. Synthetic fibres absorb very little water. Synthetic fibres are more durable than natural fibres
11. Plastics are used to make bicycle helmets, child safety seats and airbags in automobiles. They're in the cell phones, televisions, computers and other electronic equipment that makes modern life possible. They're in the roofs, walls, flooring and insulation that make homes and buildings energy efficient.
12. Cotton clothes are preferred in summer because they absorb sweat and the person feels cool whereas synthetic materials do not absorb sweat and the person feels uncomfortable
13. Rayon is made from purified cellulose, harvested primarily from wood pulp, which is chemically converted into a soluble compound. It is then dissolved and forced through a spinneret to produce filaments which are chemically solidified, resulting in fibers of nearly pure cellulose.