# class- X-2006

Time allowed: 3 hours; Maximum Marks: 75

 General Instructions: 1) The question paper comprises two Sections, A and B. You are to attempt both the Sections. 2) The candidates are advised to attempt all the questions of Section A separately and Section B separately. 3) All questions are compulsory. 4) There is no overall choice. However, internal choice has been provided in some questions. You are to attempt only one option in such questions. 5) Marks allocated to every question are indicated against it. 6) Question numbers 1—4 in Section A and 17— 18 in Section B are very short answer questions and are of 1 mark each. These are to be answered in one word or one sentence each. 7) Question numbers 5—8 in Section A and 19— 20 in Section B are short answer questions and are of 2 marks each. These are to be answered in 30—40 words each. Question numbers 9—14 in Section A and 21—23 in Section B are also short answer questions and are of 3 marks each. These are to be answered in 40—50 words each. 9) Question numbers 15—16 in Section A and 24 in Section B are long answer questions and are of 5 marks each. These are to be answered in 70 words each.

SECTION A

### Question 1

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

### Question 2

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

### Question 3

A ray of light is incident on a convex mirror as shown below:
Redraw the above diagram after completing the path of the light ray after reflection from the mirror.

### Question 4

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

### Question 5

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.

### Question 6

(1) Draw a diagram to show how two resistors R1 and R2 are connected in series.
(2) In a circuit if the two resistors of 5 ohm and 10 ohm are connected in series, compare the currents passing through the two resistors.

OR

A bulb is rated at 5.0 volt, 100 m A. Calculate its (i) power and (ii) resistance.

### Question 7

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. (Out of syllabus)

### Question 8

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
1. Lemon juice,
2. Distilled water,
3. 1 M sodium hydroxide solution,
4. Tomato juice

### Question 9

Distinguish between natural and artificial satellites.

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

1. Horizontal velocity required for the push?

2. Height to lift the satellite from the ground?

### Question 10

1. Name the raw materials used in the manufacture of sodium carbonate by Solvay process.
2. How is the sodium hydrogen carbonate formed during Solvay process separated from a mixture of NH4Cl and NaHCO3?
3. How is sodium carbonate obtained from sodium hydrogen carbonate?

### Question 11

What is the action on litmus of:
1.a Dry ammonia gas
2. bSolution of ammonia gas in water.
2. State the observations you would make on adding ammonium hydroxide to aqueous solutions of:
1.a Ferrous sulphate
2. Aluminium chloride.

### Question 12

1. How is methanal obtained from methanol?
2. Write the chemical equation of the reaction involved in the preparation of methanal from methanol.
3. Mention one use of an aqueous solution of methanal in the biology laboratory.

(Out of syllabus)
OR

Complete the following reaction equations:
1.  CH3CH2OH + H2(Out of syllabus)
2. HCHO + H2(Out of syllabus)
3.  CH3COOH + C2H5OH

### Question 13

(a) Name the four gases commonly present in biogas

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

### Question 14

What is a nuclear reactor? State one function each of

1. Coolant and

2. moderator in a nuclear reactor. (3marks)

### Question 15

(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.

### Question 16

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:
1. Stainless steel
2. Brass

SECTION B

### Question 17

Name the type of fission carried out by Amoeba.

### Question 18

Write the expanded form of AIDS.

### Question 19

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

### Question 20

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

### Question 21

Write the functions of the following in the digestive process:
1.Bile
2.Bicarbonate secreted by the duodenal
3.Pancreatic amylase.

### Question 22

Give reasons for the following:
1. The glottis is guarded by epiglottis.
2. The lung alveoli are covered with blood capillaries.
3. The wall of trachea is supported by cartilage rings.

### Question23

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

### Question 24

1. Draw a diagram of the human urinary system and label in it:
1.Kidney
2. Ureter