P-1 Carbon Compounds — Science STD 10 — Question

Liquid ammonia is used in ice factory for making ice from water. If water at 20 °C is to be converted into 2 kg, ice at 0 °C, how many grams of ammonia is to be evaporated?
(Given: The latent heat of vaporization of 1 ammonia = 341 cal/g)

Explain the construction and working of the following. Draw a neat diagram and label it.
Electric motor

Every household produces a lot of material A daily. In one of the methods of disposal B, material A is burned at a very high temperature of about 1000°C in a structure called C. During this process, the organic matter present is removed as D and E whereas F is left behind (which can be dumped in a landfill site).

1. What is material A?
2. Name the method of disposal B.
3. What is structure C known as?
4. What are (i) D (ii) E, and (iii) F?
5. This method is especially suitable for the disposal of materials produced by certain institutions. Name such institutions.

Explain why the value of g is zero at the centre of the earth

In the surgical method of birth control available for males, the structures A in the reproductive system are cut and ligated (tied up) at both ends. This prevents the reproductive cells B from coming out from the organs C where they are made in the male body. Since B cannot come out from the male body, they cannot fuse with cell D in the body of a female and hence pregnancy is prevented.

1. What are structures A?
2. What are cells B?
3. Name the organs C.
4. What is cell D?
5. What is the name of this surgical procedure for birth control available to males?

Draw a neat labelled diagram to show the structure of the human eye.

What happens when a ray of light is incident normal to the interface between two media? Draw the corresponding neat and labelled diagram.

Explain: Saving energy is the need of the hour.