P-2 Disaster Management — Science STD 10 — Question

If a concave mirror has a focal length of 10cm, find the two positions where an object can be placed to give, in each case, an image twice the height of the object.

Explain the theory of evolution and mention the proof supporting it.

In the surgical method of birth control available for human females, the structures P in the reproductive system are cut and ligated (tied up) properly at both ends. This prevents the reproductive cell Q released by an organ R from entering the structures P so that Q is not available to fuse with another reproductive cell S coming from the male reproductive system. In this way, pregnancy is prevented.

1. What are structures P?
2. What is cell Q?
3. Name the organ R.
4. What is the reproductive cell S?
5. What is the name of this surgical method of birth control available to females?

State the advantages and disadvantages of using solar cells.

A unicellular animal P having no fixed shape ingests a food particle by forming temporary finger-like projections Q. The food particle is engulfed with a little surrounding water to form a temporary stomach R inside it. The chemicals S from surrounding cytoplasm enter into R and break down food into small and soluble molecules by chemical reactions. The digested food is absorbed directly into cytoplasm by the process T. The undigested food is thrown out of the body by the rupture of a cell organelle U in a process called V.

1. Name the unicellular animal P.
2. What are (i) Q, and (ii) R?
3. Name (i) chemical S, and (ii) process T.
4. Name (i) organelle U, and (ii) process V.

Write short notes on the following: Electroplating.

Which problems does the common man face due to incidences of cybercrime?

With the help of suitable diagrams, explain the mitosis in detail.

Construct ray diagrams to illustrate the formation of a virtual image using:

1. A converging lens, and.
2. A diverging lens.