Magnetic Effects of Electric Current — Science STD 10 — Question

What are vitamins? Write two types of vitamins.

Three convex lenses are available having focal lengths of 4cm, 40cm and 4m respectively. Which one would you choose as a magnifying glass and why?

What happens when ethylene gas is heated at high pressure and high temperature in the presence of suitable catalyst?

Read the following extract and answer the questions that follow:
A liberal view behind the concept of organ and body donation is that after death our body should be useful to other needful persons so that their miserable life would become comfortable. Awareness about these concepts is. increasing in our country and people are voluntarily donating their bodies.

Life of many people can be saved by organ and body donation. Blinds can regain their vision. Life of many people can be rendered comfortable by donation of organs like liver, kidneys, heart, heart valves, skin, etc. Similarly, body can be made available for research in medical studies. Many government and social organizations are working towards increasing the awareness about body donation.
1.What is the liberal view behind the organ and body donation?
2.Name any four organs that can be donated.

A bulb of 100 W is connected across a source of 200 V. Find the current drawn by it.

Atomic number of chlorine is 17. What is the number of electrons in the valence shell of the chlorine?

Explain the following reactions giving their balanced chemical equations: Calcium carbonate (Lime stone) is treated with dil. hydrochloric acid.

Give explanations for the statements: At the end of glycolysis, pyruvate molecules are obtained.

What happens when ethanol is burnt in air?

A convex lens forms a real image or a pencil at a distance of 40 cm from the lens. The image formed is of the same size as the object. Find the focal length and power of the lens. At what distance is the pencil placed from the lens?