# 10th Science Paper Solutions Set 1 : CBSE All India Previous Year 2006

General Instructions:
(i) The question paper consists of two sections, A and B. You are to attempt both the sections.
(ii) All questions are compulsory.
(iii) There is no overall choice. However, internal choice has been provided.
(iv) All questions of Section A and all questions of Section B are to be attempted separately.
(v) Questions number 1 to 4 in Section A and 17 to 18 in Section B are short answer type questions. These questions carry one mark each.
(vi) Questions number 5 to 8 in Section A and 19 to 20 in Section B are short answer type questions and carry two marks each.
(vii) Questions number 9 to 14 in Section A and 21 to 23 in Section B are also short answer type questions and carry three marks each.
(viii) Questions number 15 to 16 in section A and question number 24 in section B are long answer type questions and carry  five marks each.
Q1 :

Name the product other than water formed on burning of ethanol in air.

Carbon dioxide is formed along with water when ethanol is burnt in air.

Q2 :

How can you show that the magnetic field produced by a given electric current in the wire decreases as the distance from the increases?

A magnetic needle shows deflection when it is placed near a current-carrying electric wire. As the magnetic needle is taken away from the wire, its deflection decreases and finally the needle align itself along North−South direction. This indicates that the magnetic field produced by a given electric current in the wire decreases as the distance from the increases.

Q3 :

A ray of light is incident on a convex mirror as shown. Redraw the diagram after completing the path of the light ray after reflection from the mirror. (1) Q4 :

Why does magnesium powder react much more rapidly than magnesium ribbon with dilute sulphuric acid?

Q5 :

An object is placed at a distance of 12 cm in front of a concave mirror. It forms a real image four times larger than the object. Calculate the distance of the image from the mirror.

Q6 :

(i) Draw a diagram to show how two resistors R1 and R2 are connected in series.

(ii) In a circuit, if the two resistors of 5 ohm and 10 ohm are connected in series, how does the current passing through the two resistors compare?

OR

A bulb is rated at 5.0 volt, 100 mA. Calculate its

(i) power and

(ii) resistance

Q7 :

Name the type of nuclear reaction by which the Sun produces its energy. List two conditions which are present at the centre of the Sun responsible for this reaction.

Q8 :

Given below are the pH values of four different liquids:

7.0, 14.0, 4.0, 2.0

Which of these could be that of

(i) lemon juice,

(ii) distilled water,

(iii) 1 M sodium hydroxide solution,

(iv) tomato juice

Q9 :

Distinguish between natural and artificial satellites.

To launch an artificial satellite in an orbit around the Earth, what is the minimum:

(i) Horizontal velocity required for the push?

(ii) Height to lift the satellite from the ground?

Q10 :

(i) Name the raw materials used in the manufacture of sodium carbonate by Solvay process.

(ii) How is the sodium hydrogen carbonate formed during Solvay process separated from a mixture of NH4Cl and NaHCO3?

(iii) How is sodium carbonate obtained from sodium hydrogen carbonate?

Q11 :

(a) What is the action on litmus of:

(i) Dry ammonia gas

(ii) Solution of ammonia gas in water

(b) State the observations you would make on adding ammonium hydroxide to aqueous solutions of:

(i) Ferrous sulphate

(ii) Aluminium chloride

OR

Explain the following terms by giving one example of each.

(i) Mineral

(ii) Ore

(iii) Gangue

Q12 :

(i) How is methanal obtained from methanol?

(ii) Write the chemical equation of the reaction involved in the preparation of methanal from methanol.

(iii) Mention one test of an aqueous solution of methanal in the biology laboratory.

OR

Complete the following reaction equations:

(i) (ii) (iii) Q13 :

(i) Name the four gases commonly present in biogas.

(ii) List two advantages of using biogas over fossil fuels.

Q14 :

What is a nuclear reactor? State one function each of coolant and moderator in a nuclear reactor.

Q15 :

(a) What is an electromagnet? What does it consist of?

(b) Name one material in each case which is used to make a

(i) Permanent magnet

(ii) Temporary magnet

(c) Describe an activity to show how you can make an electromagnet in your school laboratory.

Q16 :

What is an alloy? How is an alloy made? List two purposes of making alloys. Mention the constituents and two properties of each of the following alloys:

(i) Stainless steel

(ii) Brass

Q17 :

Name the type of fission carried out by Amoeba.

Q18 :

Write the expanded form of AIDS.

Q19 :

Differentiate between tropic and nastic movements in plants. Give one example of each.

Q20 :

“Rapid increase of population disturbs the biotic environment.” Justify this statement taking any two aspects.

Q21 :

Write the functions of the following in the digestive process:

(i) Bile

(ii) Bicarbonate secreted by the duodenum

(iii) Pancreatic amylase

Q22 :

Give reasons for the following:

(i) The glottis is guarded by epiglottis.

(ii) The lung alveoli are covered with blood capillaries.

(iii) The wall of trachea is supported by cartilage rings.

Q23 :

Who proposed the “Theory of Natural Selection”? Explain this theory briefly.

Q24 :

(a) Draw a diagram of the human urinary system and label in it:

(i) Kidney

(ii) Ureter