Board Paper of Class 10 2005 Science (SET 1) - Solutions
(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 5 in Section A and 21 to 23 in Section B are short answer type questions. These questions carry one mark each.
(vi) Questions number 6 to 10 in Section A and 24 to 25 in Section B are short answer type questions and carry two marks each.
(vii) Questions number 11 to 17 in Section A and 26 to 29 in Section B are also short answer type questions and carry three marks each.
(viii) Questions number 18 to 20 in section A and question number 30 in section B are long answer type questions and carry five marks each.
- Question 1
Why does a large increase in temperature slow down a reaction catalysed by an enzyme?VIEW SOLUTION
- Question 2
Dry ammonia gas has no action on litmus paper, but a solution of ammonia in water turns red litmus paper blue, why is it so?VIEW SOLUTION
- Question 3
What is seen to happen when a piece of sodium metal is dropped into water?VIEW SOLUTION
- Question 4
Where will the image be formed by a convex mirror if the object is placed between infinity and the pole of the mirror?VIEW SOLUTION
- Question 5
Should the heating element of an electric iron be made of iron, silver or nichrome wire?VIEW SOLUTION
- Question 6
What are the raw materials used in the manufacture of Portland Cement? What is Reinforced Cement Concrete (RCC)?VIEW SOLUTION
- Question 7
Name the catalyst used in the manufacture of ammonia by Haber’s Process. How is the ammonia formed separated from the other gases?VIEW SOLUTION
- Question 8
Describe a method for finding out the exact North-South direction at a place using the direction of sunlight.VIEW SOLUTION
- Question 9
In what S.I. units is the power of lenses stated? A convex lens has a focal length of 50 cm. Calculate its power.VIEW SOLUTION
- Question 10
Describe a nuclear chain reaction with an example.VIEW SOLUTION
- Question 11
How did Arrhenius define acids and bases? Choose a strong acid and a weak base from the following substances:
CH3COOH, NH4OH, HC1, KOHVIEW SOLUTION
- Question 12
Draw a labelled diagram of the Frasch Process for obtaining sulphur from places deep underground.VIEW SOLUTION
- Question 13
What are detergents? What change has been made in detergents to make them easily bio-degradable? Explain the cleansing action of detergents.VIEW SOLUTION
- Question 14
(a) Write a chemical equation to show how ethanol can be converted into ethanoic acid.
(b) Describe the action of ethanoic acid on sodium carbonate solution.
(c) Complete the following reaction equation:
CH3COONa (s) + NaOH (s)
Define the term, ‘fermentation’. Name the enzyme which converts
(i) milk into curd (yogurt)
(ii) cane sugar into glucose and fructose, and
(iii) glucose into ethanolVIEW SOLUTION
- Question 15
A steady current is passed for 30 minutes through two voltameters connected in series:
a copper voltameter [Cu cathode in CuSO4 solution], and a silver voltameter [Ag cathode
in AgNO3 solution]. If the mass of copper deposited in the first voltameter is 21.17 g;
calculate the mass of silver deposited on the cathode in the other voltameter.
Given: Relative Atomic mass of Cu = 63.5, Ag = 108.0.VIEW SOLUTION
- Question 16
What is meant by the combustion of CH4 ? List the three essential requirements for any combustion to take place. Give reasons for the difficulty experienced in burning a piece of wood if (i) it is wet, (ii) it is large in size.VIEW SOLUTION
- Question 17
State the composition of the three main layers of the earth, centre outwards.VIEW SOLUTION
- Question 18
Describe with examples the following steps associated with the extraction of metals from their ores:
(i) Froth-floatation process
(ii) Roasting of an ore
(iii) Calcination of an ore
Differentiate between an ‘alloy’ and an ‘amalgam’. How are alloys made? State with examples any two properties in which an alloy may be different from those of its constituents.
Write the constituents and special advantages of:
(i) Stainless steel
(ii) MagnaliumVIEW SOLUTION
- Question 19
What are ‘simple’ and ‘compound’ microscopes? Draw a labelled ray diagram showing the image formed by a compound microscope. State the formula used to calculate the magnification produced by a compound microscope. What is the maximum magnification generally possible by using a compound microscope?
(a) Explain how we see different colours of an object.
(b) Why is it that some persons cannot distinguish between different colours?
(c) The chick wakes up with the sunrise and sleeps by the sunset. How does it manage?VIEW SOLUTION
- Question 20
State Fleming’s left-hand rule. With a labelled diagram, describe the working of an electric motor. What is the function of split ring commutator in a motor?VIEW SOLUTION
- Question 21
How are inheritary disorders explained?VIEW SOLUTION
- Question 22
State any harmful effect of lead present as pollutant in air.VIEW SOLUTION
- Question 23
What are occupational disorders? State briefly how Pneumoconiosis or Byssinosis is caused.VIEW SOLUTION
- Question 24
State two main objectives of Environmental Laws passed by the Government of India.
Mention names of any two such laws.
List any four practices which help in protecting our environment.VIEW SOLUTION
- Question 25
List two vital functions of the human kidney. Draw a labelled diagram of an artificial kidney.VIEW SOLUTION
- Question 26
Draw a diagram showing endocrine glands in a male body. Label the following glands on it:
(iv) TestesVIEW SOLUTION
- Question 27
Define any three of the following terms used in relation to human reproduction:
(v) ParturitionVIEW SOLUTION
- Question 28
Mention briefly the salient points of any one of the following theories of evolution:
(i) Lamarck’s theory
(ii) Darwin’s theoryVIEW SOLUTION
- Question 29
How is ‘respiration’ different from ‘breathing’? Explain the processes of ‘aerobic’ respiration and ‘anaerobic’ respiration.VIEW SOLUTION