[ Question Bank ] - 2022 — Science STD 10 — Question

Name the defect of vision which can be corrected by a diverging lens. Show clearly by a ray diagram how the lens corrects the defect.

Giving their structures, state the number of single bonds, double bonds and triple bonds in the following compounds:

1. Ethyne.
2. Ethene.
3. Benzene.

Compare and contrast biomass and hydroelectricity as sources of energy.

How does the tendency to lose electrons change as we go down in group 1 of the periodic table? Why does it change this way?

Leaves of a healthy potted plant were coated with vaseline. Will this plant remain healthy for long? Give reason for your answer.

A convex lens produces an inverted image magnified three times of an object placed at a distance of 15cm from it. Calculate focal length of the lens.

Observe the following diagram. Write the answers of the following questions.

i. To which phylum does the animal included in the diagram belong?
ii. What is the exoskeleton made up?
iii. What is the symmetry?

Explain briefly, how rainwater harvesting is done from open spaces around the buildings in city areas.

In the nuclear reactor of a power plant:

1. How do control rods control the rate of fission?
2. How is heat removed from the reactor core, and what use is made of this heat?

When a piece of limestone reacts with dilute HCl, a gas X is produced. When gas X is passed through lime water then a white precipitate Y is formed. On passing excess of gas X, the white precipitate dissolves forming a soluble compound Z.

1. What are X, Y and Z?
2. Write equations for the reactions which take place:

1. When limestone reacts with dilute HCl.
2. When gas X reacts with lime water to form white precipitate Y.
3. When excess of gas X dissolves white precipitate Y to form a soluble compound Z.