Board Paper of Class 10 2009 Science (SET 1) - Solutions
(i) The question paper comprises 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 in all the three questions of five marks category. Only one option in such questions is to be attempted
(iv) All questions of Section A and all questions of Section B are to be attempted separately
(v) Questions number 1 to 6 in Section A and 17 to 19 in Section B are short answer type questions. These questions carry one mark each
(vi) Questions number 7 to 10 in Section A and 20 to 24 in Section B are short answer type questions and carry two marks each
(vii) Questions number 11 to 14 in Section A and 25 and 26 in Section B are also short answer type questions and carry three marks each
(viii) Questions number 15 and 16 in section A and question number 27 in section B are long answer type questions and carry five marks each
- Question 1
In electrolysis of water, why is the volume of gas collected over one electrode double that of gas collected over the other electrode?VIEW SOLUTION
- Question 2
What effect does an increase in concentration of H+ (aq.) in a solution have on the pH of solution?VIEW SOLUTION
- Question 3
What happens when a small piece of sodium is dropped into ethanol?VIEW SOLUTION
- Question 4
Draw a schematic diagram of an electric circuit consisting of a battery of two cells each of 1.5 V, 5 Ω, 10 Ω and 15 Ω resistors and a plug key, all connected in series.VIEW SOLUTION
- Question 5
When is the force experienced by a current-carrying conductor placed in a magnetic field the largest?VIEW SOLUTION
- Question 6
State the rule which gives the direction of magnetic field associated with a current-carrying conductor.VIEW SOLUTION
- Question 7
(i) Name the products formed when sodium hydrogen carbonate is heated.
(ii) Write the chemical equation for the reaction involved in the above.VIEW SOLUTION
- Question 8
(i) What is observed when a solution of potassium iodide is added to a solution of lead nitrate taken in a test tube?
(ii) What type of reaction is this?
(iii) Write a balanced chemical equation to represent the above reaction.VIEW SOLUTION
- Question 9
What is an electric circuit? Distinguish between an open and a closed circuit.VIEW SOLUTION
- Question 10
Calculate the resistance of an electric bulb which allows a 10 A current when connected to a 220 V power source.VIEW SOLUTION
- Question 11
(a) What is meant by periodicity in properties of elements with reference to the periodic table?
(b) Why do all the elements of the same group have similar properties?
(c) How will the tendency to gain electrons change as we go from left to right across a period? Why?VIEW SOLUTION
- Question 12
(a) Distinguish between esterification and saponification reactions of organic compounds.
(b) With a labelled diagram describe an activity to show the formation of an ester.VIEW SOLUTION
- Question 13
For which position of the object does a convex lens form a virtual and erect image? Explain with the help of a ray diagram.VIEW SOLUTION
- Question 14
(a) Define the term ‘volt’.
(b) State the relation between work, charge and potential difference for an electric circuit.
Calculate the potential difference between the two terminals of a battery if 100 joules of work is required to transfer 20 coulombs of charge from one terminal of the battery to the other.VIEW SOLUTION
- Question 15
(a) Distinguish between ionic and covalent compounds under the following properties:
(i) Strength of forces between constituent elements
(ii) Solubility of compounds in water
(iii) Electrical conduction in substances
(b) Explain how the following metals are obtained from their compounds by the reduction process:
(i) Metal M which is in the middle of the reactivity series.
(ii) Metal N which is high up in the reactivity series.
Give one example of each type
(a) Distinguish between ‘roasting’ and ‘calcination’. Which of these two is used for sulphide ores and why?
(b) Write a chemical equation to illustrate the use of aluminium for joining cracked railway lines.
(c) Name the anode, the cathode and the electrolyte used in the electrolytic refining of impure copper.VIEW SOLUTION
- Question 16
(a) What is dispersion of white light. What is the cause of such dispersion. Draw a diagram to show the dispersion of white light by a glass prism.
(b) A glass prism is able to produce the spectrum when white light passes through it, but a glass slab doesn’t produce any spectrum. Explain why it is so.VIEW SOLUTION
- Question 17
Which compounds are responsible for the depletion of ozone layer?VIEW SOLUTION
- Question 18
Why is DNA copying an essential part of the process of reproduction?VIEW SOLUTION
- Question 19
Where does digestion of fat take place in our body?VIEW SOLUTION
- Question 20
How is charcoal obtained from wood? Why is charcoal considered a better fuel than wood?VIEW SOLUTION
- Question 21
Describe how hydro-energy can be converted into electrical energy. Write any two limitations of hydro-energy.VIEW SOLUTION
- Question 22
What is Chipko movement? Why should we conserve forests?VIEW SOLUTION
- Question 23
Suggest any four changes that you would like to be incorporated in the life-style of students of your age to move towards a sustainable use of available resources.VIEW SOLUTION
- Question 24
Describe the role of the following in human beings:
(i) Seminal vesicles
(ii) Prostate glandVIEW SOLUTION
- Question 25
What is ‘Phototropism’? How does it occur in plants? Describe an activity to demonstrate phototropism.VIEW SOLUTION
- Question 26
Explain how the sex of the child is determined at the time of conception in human beings.VIEW SOLUTION
- Question 27
(a) Draw a sectional view of the human heart and label on it Aorta, Pulmonary arteries, Vena cava, Left ventricle.
(b) Why is double circulation of blood necessary in human beings?