Control and Coordination — Science STD 10 — Question

What are the limitations of the energy that can be obtained from the oceans?

What is washing soda? State two properties and two uses of washing soda.

When zinc metal is treated with a dilute solution of a strong acid, a gas is evolved, which is utilised in the hydrogenation of oil. Name the gas evolved. Write the chemical equation of the reaction involved and also write a test to detect the gas formed.

An object is placed at a distance of 100cm from a converging lens of focal length 40cm.

1. What is the nature of image?
2. What is the position of image?

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.

What would your image look like if you stood dose to a large:

1. Convex mirror?
2. Concave mirror?

Give reasons for your answer.

Name five places in India where nuclear power plants are located.

When is a person said to have developed cataract in his eye ? How is the vision of a person having cataract restored?

Why is chemical communication better than electrical impulses as a means of communication between cells in a multi-cellular organism?

Calculate the cost of operating a heater of 500W for 20hours at the rate of? ₹3.90 per unit.

Metallic oxides of zinc, magnesium and copper were heated with the following metals.

Metal	Zinc	Magnesium	Copper
Zinc oxide	----	----	----
Magnesium oxide	----	----	----
Copper oxide	----	----	----

In which cases will you find displacement reactions taking place?