CBSE Board Class 10 Science Sample Papers 2011

Class – X
Subject –Science

Instructions      
                                    
I. This question paper is divided into two sections A and B.
II. All questions are compulsory.
III. Q. No. 1 to 5 in section A are 1 mark questions.
IV. Q. No. 6 to 10 are 2 mark questions.
V. Q. No. 11 to 15 are 3 mark questions
VI. Q. No. 16 & 17 are 5 mark questions.
VII. Q. No. 18 to 27 in section B are multiple choice questions and are of 1 mark questions.
Section A

Q1.Define lateral magnification.

Q2.A person cannot see object beyond 1.2m distinctly. What is the defect and how can it be corrected?

Q3. What will be the color of sky in the absence of atmosphere? Why?

Q4. A metal A forms an oxide having formula A2O3. It belongs to 3rd period in the periodic table. Write its atomic no. and valency.

Q5. What happens when a small piece of sodium is dropped into ethanol?

Q6. What are rod shaped and cone shaped cells?How do they help us in seeing colors?

Q7. What is the difference between virtual image produced by concave, plane and convex mirrors?

Q8.Name:

a. Three elements that have a single electron in their outermost shells.
b. Two elements that have two electrons in their outermost shell.
c. Three elements with filled outermost shell.

Q9.

Groups →
Periods  1     2  3 to 12   13     14     15      16     17    18
     2     A        B      C
     3      D      E       F


a. Which element will form only covalent compounds?
b. Which element is a metal with valency 2?
c. Which element is nonmetal with valency of 3?
d. Out of D and E, which one has a bigger atomic radius and why?
e. Write a common name for the family of elements C and F.

Q10.Two carbon compounds A and B have the molecular formula C3H8 and C3H6respectively. Which one of the two is most likely to show addition reaction?
Justify your answer. Explain how addition reaction is useful in vegetable ghee industry?

Q11. Write the sign conventions used for spherical mirrors?

Q12. A concave mirror and a concave lens are held in water. What changes, if any, do you expect in their focal length?

Q13.Table given below shows a part of the periodic table.

  H           He
  Li    Be      B      C      N      O      F      Ne
  Na    Mg      Al      Si      P      S      Cl      Ar

Using this table, explain why:

a. Li and Na are considered as active metals?
b. Atomic size of Mg is less than that of Na?
c. F is more reactive than Cl?

Q14. What is color blindness?

Q15. Give differences between Diamond and Graphite.

Q16.

a. Give a chemical test to distinguish between saturated and unsaturated hydrocarbons.

b. Name the product formed when ethanol burns in air.
c. What two forms of energy are liberated on burning alcohol?
d. Why the reaction between methane and chlorine is considered a substitution reaction

Q17. Give reasons of the following;
a. The sky near the horizon appears to have reddish view at the time of sunrise and sun set.
b. The sky appears dark to an astronaut.
c. The planets do not twinkle.

Section B
Q18. Power of lens is-
A. P = 1/ f(m)
B. P = f (m)
C. 1/P  =   1/f (m)
D. P  - f (m) = 1

Q19. If a person obtains a blurred image of an object on a screen by using a concave mirror, in order to obtain a sharp image on the screen, he will have to shift the mirror:
A. Towards the screen
B. Away from the screen
C. To a position very far away from the screen
D. Either towards or away from the screen depending upon the position of the object.

Q20. Focal length of plane mirror is:
A. 0
B. +1
C. -1
D. infinity

Q21. The human eye forms the image of an object at its :

A. Cornea
B. Retina
C. Pupil
D. Iris

Q22. The splitting of white light into its component colors is called:

A. Dispersion
B. Spectrum
C. Image
D. Rainbow

Q23. No. of triads identified by Dobereiner were:

A. 2
B. 3
C. 4
D. 5

Q24. How many elements were classified by Newland?

A. 50
B. 53
C. 56
D. 60

Q25. Choose the metalloid out of the following:

A. Boron
B. Sodium
C. Magnesium
D. Fluorine

Q26. The allotropes of Carbon are
A. C-12, C-13
B. C-12, C-14
C. C-12, diamond
D. Diamond and Graphite

Q27. Vinegar is a dilute solution of:

A. Acetic acid
B. Formic acid
C. Ethanol
D. Methanol