Questions

The required number is SEVEN.

If you remove  S, it becomes EVEN.

Magnetism in materials is due to circular motion of electrons.

Nuclear Power Plant uses a Non Renewable Energy Source.

Non-renewable energy is that source of energy which can not be used again and again. This sort of energy is sustainable to exhaustion.

Non renewable energy is that form of energy which is subject to deletion. This type of energy is of many uses to us. It can be used to produce electricity, heating, cooking, transportation and manufacturing. 85% of the energy used in the industrial processes is form the non-renewable type of energy.

A pulse is an edible seed that grows in a pod. Pulses include all beans, peas, and lentils.
Pulses are a great source of protein.

This means they can be particularly important for people who do not get protein by eating meat, fish or dairy products.

However, pulses can also be a healthy choice for meat-eaters. You can add pulses to soups, casseroles and meat sauces to add extra texture and flavor. This means you can use less meat, which makes the dish lower in fat and cheaper.

Air contains water in a gaseous form called water vapour.

China blocked wikipedia in all languages recently in May 2019.

The main difference lies in the motive of the two parties. The main motive of the hedger is to hedge(minimize) the risk from the occurence of some events. 

The motive of the speculator is to gamble in the market in order to make the profit by buying/selling the derivative products.