Question

1. Why do we wrap a blanket around a person whose clothes have caught fire?

2. Why curd set faster in summer than in winter?

3. Why are the handles of pressure cooker made up of plastic? Name the type of the plastic.

4. Why is it necessary to conserve forest?

5. Why zinc can displace copper from copper sulphate solution?

6. Why methane and LPG are considered as ecofriendly fuel?

7. Why Aluminum is not used to make electrical wire when it is cheaper and lighter than silver?

8. Why drip irrigation considered as best method of irrigation?

9. Why is white phosphorous is stored under water?

10. Why hydrogen is used as rocket fuel?

Q4) Read the passage and answer the following question:

Some microorganisms are useful to us in many ways. A bacterium called Lactobacillus is useful in making curd

from milk. Milk contain lactose, curd contains the bacterium Lactobacillus that helps to convert lactose in the milk

to lactic acid. In this way curd is formed from milk.​

Answer 1

Answer:

1 Tocut off the supply of air around the person

Answer 2

Q . no: 10)

Explanation:

A light and extremely powerful rocket propelled has the lowest molecular weight of any known substance and burns with extreme intensity . ( 5,500 degree F ) .

So that's why hydrogen is used as Rocket fuel.