Electricity — Science STD 10 — Question

i. Predict the reaction, if any, between
a. zinc and silver nitrate solution,
b. magnesium and iron (II) chloride solution,
c. copper and magnesium sulphate solution.
Write the equations, with its physical form symbols, for the reaction.
ii. A lump of element X can be cut by a knife. During its reaction with water, X floats and melts. What is X? Explain.

Two resistances when connected in parallel give resultant value of 2 ohm; when connected in series the value becomes 9 ohm. Calculate the value of each resistance.

What do you understand by the term “electromagnetic induction”? Explain with the help of a diagram.

What is the nuclear fuel in the sun? Describe the process by which energy is released in the sun. Write the equation of the nuclear reaction involved.

What is the difference between a reflex action and walking?

Some of the important fossils which have been studied are those of organisms X, Y and Z. X were marine arthropods which were common between 400 to 600 million years ago. Y were the invertebrate animals (molluscs) with a flat, coiled, spiral shell which lived in the sea about 180 million years ago. Z are the extinct carnivorous or herbivorous reptiles which appeared on the earth about 250 million years ago and became extinct about 65 million years ago. What are X, Y and Z?

What is the difference between regular reflection of light and diffuse reflection of light? What type of reflection of light takes place from:

1. A cinema screen.
2. A plane mirror.
3. A cardboard.
4. Still water surface of a lake

Define the terms:

1. mineral.
2. ore.
3. gangue.

What happens when a concentrated solution of sodium chloride is electrolysed? Write the equation of the reaction involved.

There are two types of light-sensitive cells in the human eye:

1. Where are they found?
2. What is each type called?
3. To what is each type of cell sensitive?