English Medium इयत्ता १० - CBSE Question Bank Solutions for Science

Two metals X and Y form the salts XSO₄ and Y₂SO₄, respectively. The solution of salt XSO₄ is blue in colour whereas that of Y₂SO₄ is colourless. When barium chloride solution is added to XSO₄ solution, then a white precipitate Z is formed along with a salt which turns the solution green. And when barium chloride solution is added to Y₂SO₄ solution, then the same white precipitate Z is formed along with colourless common salt solution.

1. What could the metals X and Y be?
2. Write the name and formula of salt XSO₄.
3. Write the name and formula of salt Y₂SO₄.
4. What is the name and formula of white precipitate Z?
5. Write the name and formula of the salt which turns the solution green in the first case.

A metal salt MX when exposed to light splits up to form metal M and a gas X₂. Metal M is used in making ornaments whereas gas X₂ is used in making bleaching powder. The salt MX is itself used in black and white photography.

1. What do you think metal M is?
2. What could be gas X₂?
3. Name the metal salt MX.
4. Name any two salt solutions which on mixing together can produce a precipitate of salt MX.
5. What type of chemical reaction takes place when salt MX is exposed to light? Write the equation of the reaction.

Name the defect of vision in a person: 

 whose near point is more than 25 on away.  

Name the defect of vision in a person: 

whose far point is less than infinity

 Which defect of vision can be rectified: 

by using a concave lens?

Which defect of vision can be rectified: 

 by using a convex lens?

What is the other name for 

 myopia

What is the other name for 

 hypermetropia

What is the scientific name of 

short-sightedness

What is the scientific name of 

long-sightedness?

Name the defect of vision in which the eye-lens loses its power of accommodation due to old age.

Name the defect of vision which makes the eye-lens cloudy resulting in blurred vision.

What is the other name of old age hypermetropia?

Name any two defects of vision which can be corrected by using spectacles.

Name one defect of vision (or eye) which cannot be corrected by any type of spectacle lenses.

Name the body part with which the terms myopia and hypermetropia are connected.

What is the far point of a person suffering from myopia (or short-sightedness)?

Where is the near point of a person suffering from hypermetropia (or long-sightedness)?

Your friend can read a book perfectly well but cannot read the writing on blackboard unless she sits on the front row in class.

1. Is she short-sighted or long-sighted?
2. What type of lenses-converging or diverging-would an optician prescribe for her?

Your friend can read a book perfectly well but cannot read the writing on blackboard unless she sits on the front row in class. 

 What type of lenses-converging or diverging-would an optician prescribe for her?