CBSE Class 10 Science Question Paper 2009 (1)

CBSE Class 10 Science Question Paper 2009 (1). Students can download the last year question papers using the link below. Free download of examination question papers with solutions. Last 10 year question papers should be practised to get better marks in examinations.

SCIENCE (Theory)

SECTION – A

Q1. Name a reducing agent that may be used to obtain manganese from manganese dioxide.

Q2. Balance the following chemical equations:

 Pb (NO₃)₂ (s) ↔heat PbO (s) + NO₂ (g) + O₂ (g)

Q3. Why does tooth decay start when the pH of mouth is lower than 5.5? 

Q4. Why does sky look blue on a clear day?

Q5. Why does a ray of light bend when it travels form one medium into another? 

Q7. What is an oxidation reaction? Give an example of oxidation reaction. Is oxidation an exothermic or an endothermic reaction? 

Q8. A compound which is prepared from gypsum has the property of hardening when mixed with a proper quantity of water. Identify the compound. Write the chemical equation for its preparation. For what purpose is it used in hospitals?

Q9. A wire is 1.0 m long, 0.2 mm in diameter and has a resistance of 10W. Calculate the resistively of its material.

Q10. What is the minimum number of rays required for locating the image formed by a concave mirror for an object? Draw a ray diagram to show the formation of a virtual image by a concave mirror.

Q11. Give reasons for the following observations: 

(a) The element carbon forms a very large number of compounds.

(b) Air holes of gas burner have to be adjusted when the heated vessels get blackened by the flame.

(c) Use of synthetic detergents causes pollution of water.

Please click the link below to download pdf file of  CBSE Class 10 Science Question Paper 2009 (1)