CBSE Board Class X Science Question Paper

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Few Sample Questions from CBSE Class 10th Science Question Paper Set 1 SA - II are as follows:

Q. Write the number or vertical columns in the modem periodic table. What arc these columns called?

Q. Draw a ray diagram to show the path or the reflected ray corresponding to an incident ray which is directed towards the principal focus or a convex mirror. Mark on it the angle of incidence and the angle of reflection.

Q. Write the name and general formula or a chain of hydrocarbons in which an addition reaction with hydrogen can take place. Stating the essential conditions required for an addition reaction to occur write the chemical equation giving the name of the reactant and the product or such a reaction.

Q. When you add about 2 ml. of acetic acid to a test tube containing an equal amount or distilled water and leave the test tube to settle after shaking its contents, then after about 5 minutes what will you observe in the test tube:

(A) A white precipitate settling at its bottom.
(B) A clear colourless solution.
(C) A layer or water over the layer of acetic acid, or
(D) A layer or acetic acid over the layer of water.

Get the Guess Papers for CBSE Class 10th
Q. (a) Give one example each of a unisexual and a bisexual flower.
(b) Mention the changes a flower undergoes after fertilization.
(c) How does the amount or DNA remain constant though each new generation is a combination of DNA copies of two individuals?

List any two properties of the elements belonging to the first group of the modern periodic table.

What is a gene?

Give one example each from your daily life where the domestic waste can be effectively reused and recycled.

What is the main difference between sperms and eggs of humans? Write the importance of this difference.

List two possible ways in which a concave mirror can produce a magnified image of an object placed in front of it. State the difference, if any, between these two images.

What are decomposers? List two important roles they play in the environment.

Why is sustainable management of natural resources necessary? Out of the two methods reuse and recycle which one would you suggest to practise and why?

What are homologous series of carbon compounds? Write the molecular formula of two consecutive members of homologous series of aldehydes. State which part of these compounds determines their (i) physical and (ii) chemical properties.

A carboxylic acid (molecular formula C2H4O2) reacts with an alcohol in the presence of an acid catalyst to form a compound 'X'. The alcohol on oxidation with alkaline KMnO4 followed by acidification gives the same carboxylic acid C2H4O2. Write the name and structure of (i) carboxylic acid, (ii) alcohol and (iii) the compound 'X'.

The electrons in the atoms of four elements A, B, C and D are distributed in three shells having 1, 3, 5 and 7 electrons in the outermost shell respectively. State the period in which these elements can be placed in the modern periodic table. Write the electronic configuration of the atoms of A and D and the molecular formula of the compound formed when A and D combine.

Study the following table in which positions of six elements A, B, C, D, E and F are shown as they are in the modern periodic table:

On the basis of the above table, answer the following questions:

(i) Name the element which forms only covalent compounds.
(ii) Name the element which is a metal with valency three.
(iii) Name the element which is a non-metal with valency three.
(iv) Out of D and E, which is bigger is size and why?
(v) Write the common name for the family to which the elements C and F belong.

Explain the process of regeneration in Planaria. How is this process different from reproduction?

What is placenta? State its function in human female.

With the help of suitable examples, explain why certain traits cannot be passed on to the next generation. What are such traits called?

"A trait may be inherited, but may not be expressed." Justify this statement with the help of a suitable example.

A student wants to project the image of a candle flame on a screen 60 cm in front of a mirror by keeping the flame at a distance of 15 cm from its pole.

(a) Write the type of mirror he should use.
(b) Find the linear magnification of the image produced.
(c) What is the distance between the object and its image?
(d) Draw a ray diagram to show the image formation in this case.

Draw a ray diagram to show that path of the refracted ray in each of the following cases :
A ray of light incident on a concave lens is

(i) passing through its optical centre.

(ii) parallel to its principal axis.

(iii) directed towards its principal focus.

A narrow beam PQ of white light is passing through a glass prism ABC as shown in the diagram.

Trace it on your answer sheet and show the path of the emergent beam as observed on the screen DE.
(i) Write the name and cause of the phenomenon observed.
(ii) Where else in nature is this phenomenon observed ?
(iii) Based on this observation, state the conclusion which can be drawn about the constituents of white light.

"Energy flow in a food chain is unidirectional." Justify this statement. Explain how the pesticides enter a food chain and subsequently get into our body.

Elements forming ionic compounds attain noble gas configuration by either gaining or losing electrons from their outermost shells. Give reason to explain why carbon cannot attain noble gas configuration in this manner to form its compounds. Name the type of bonds formed in ionic compounds and in the compounds formed by carbon. Also give reason why carbon compounds are generally poor conductors of electricity.

(a) Draw a sectional view of human female reproductive system and label the part where

(i) eggs develop.
(ii) fertilisation take place.
(iii) fertilised egg gets implanted.

(b) Describe, in brief, the changes the uterus undergoes.

(i) to receive the zygote.
(ii) if zygote is not formed.

(a) Name the parts labelled as A, B, C and D in the diagram given below:

(b) What is pollination? State its significance.
(c) How does fertilisation occur in flowers? Name the parts of the flower that develop into (i) seed, and (ii) fruit after fertilisation.

(a) Explain the following terms related to spherical lenses :

(i) optical centre
(ii) centres of curvature
(iii) principal axis
(iv) aperture
(v) principal focus
(vi) focal length

(b) A converging lens has focal length of 12 cm. Calculate at what distance should the object be placed from the lens so that it forms an image at 48 cm on the other side of the lens.

(a) List the parts of the human eye that control the amount of light entering into it. Explain how they perform this function.
(b) Write the function of retina in human eye.
(c) Do you know that the corneal-impairment can be cured by replacing the defective cornea with the cornea of the donated eye? How and why should we organise groups to motivate the community members to donate their eyes after death?

In an experiment to study the properties of ethanoic acid, a student takes about 3 mL of ethanoic acid in a dry test tube. He adds an equal amount of distilled water to it and shakes the test tube well. After some time he is likely to observe that
(A) a colloid is formed in the test tube.
(B) the ethanoic acid dissolves readily in water.
(C) the solution becomes light orange.
(D) water floats over the surface of ethanoic acid.

A student takes about 2 mL ethanoic acid in a dry test tube and adds a pinch of sodium hydrogen carbonate to it. He reports the following observations:
I. Immediately a colourless and odourless gas evolves with a brisk effervescence.
II. The gas turns lime water milky when passed through it.
III. The gas burns with an explosion when a burning splinter is brought near it.
IV. The gas extinguishes the burning splinter that is brought near it.
The correct observations are
(A) I, II and III
(B) II, III and IV
(C) III, IV and I
(D) I, II and IV

We need 20% aqueous solution of sodium hydroxide for the study of saponification reaction. When we open the lid of the bottle containing solid sodium hydroxide we observe it in which form?

(A) Colourless transparent beads
(B) Small white beads
(C) White pellets/flakes
(D) Fine white powder