Board Paper of Class 10 2013 Chemistry - Solutions

• Question 16
  Identical twins are syngenic with similar chromosomal contents. Natural clones are those who possess identical chromosomes. Fill up with the suitable word given in the brackets.
  
  (a) Identical twins are __________.

  (natural clones/induced clones)

  
  (b) Identical twins are __________.

  (dissimilar to each other/similar to each other)

  VIEW SOLUTION

• Question 17
  Kavitha is suffering from common cold. What are the questions you will put forth to Kavitha to confirm the disease?
  (a) __________
  (b) __________ VIEW SOLUTION

• Question 18
  Copy the diagram given below and write the names of A and B in the parts of thyroid gland.
  
  VIEW SOLUTION

• Question 19
  Correct the statements if they are wrong.
  (a) Alpha cells produce insulin and beta cells produce glucagon.
  (b) Ovary produces eggs and androgen. VIEW SOLUTION

• Question 20
  This diagram is of human brain, and the functions given below are to be marked as (a) and (b).
  
  
   
  (a) Sight of smell
  (b) Sight of vision VIEW SOLUTION

• Question 21
  Composite fruit is formed by all the flowers of __________; __________ fruit is developed from a single flower with multicarpellary apocarpous superior ovary. VIEW SOLUTION

• Question 22
  One of the following groups contains non-mammalian animal. Pick up the group :
  (a) dolphin, walrus, porcupine, rabbit, bat
  (b) elephant, pig, horse, donkey, monkey
  (c) antelope, deer, cow, buffalo, blackbuck
  (d) dog, cat, crocodile, lion, tiger VIEW SOLUTION

• Question 23
  Based on relationship, fill up :
  Whale Baleen plates
  Bat : __________ VIEW SOLUTION

• Question 24
  Fill in the blanks :
  Plasma: Fibrinogen, RBC : Carriage of oxygen
  WBC : __________ VIEW SOLUTION

• Question 25
  Observe the diagram :
  
  
  
  (a) Mention the type of movements shown in figure A and B.
  (b) How does the movement differ from the movement of mimosa? VIEW SOLUTION

• Question 26
  Study the food chain below, correct it and convert into a pyramid of energy.
  Mulberry → Sparrow → Caterpillar → Kite VIEW SOLUTION

• Question 27
  Odd man out :
  (a) bio alcohol, green diesel, bio ethers, petroleum
  (b) cholera, typhoid, scabies, dysentery VIEW SOLUTION

• Question 28
  A non renewable resource is a natural resource if it is replaced by natural process at a rate comparable or faster than its rate of consumption by humans.
  Read this statement and confirm whether it is correct or incorrect. If it is incorrect give the correct statement. VIEW SOLUTION

• Question 29
  Pick out the suitable appliances to conserve the electric energy.
  (Florescent bulbs, copper choke, solar water heater, electric water heater, tungsten bulbs, electronic choke) VIEW SOLUTION

• Question 30
  Distinguish between true solution and colloidal solution. VIEW SOLUTION

• Question 31
  Find the concentration of solution in terms of weight percent if 20 gm of common salt is dissolved in 50 gm of water. VIEW SOLUTION

• Question 32
  Calculate the gram molecular mass of water from the values of gram atomic mass of hydrogen and of oxygen.
  Gram atomic mass of hydrogen =1 g
  Gram atomic mass of oxygen =16 g VIEW SOLUTION

• Question 33
  The pH values of certain familiar substances are given below :
   

  Substance	pH value
  Blood Baking soda Vinegar Household ammonia	7.4 8.2 2.5 12

  
  Analyse the data in the table and answer the following questions :
  (a) Which substances are acidic in nature?
  (b) Which substances are basic in nature? VIEW SOLUTION

• Question 34
  Why does the colour of copper sulphate change when an iron nail is kept in it? Justify your answer. VIEW SOLUTION

• Question 35
  Write any two uses of aluminium. VIEW SOLUTION

• Question 36
  To design the body of the aircraft, aluminium alloys are used. Give your reasons. VIEW SOLUTION

• Question 37
  Diamond is the hardest allotrope of carbon. Give reason for its hardness. VIEW SOLUTION

• Question 38
  Fill in the blanks :
  (a) Force = mass × acceleration, then momentum = __________.
  (b) Liquid hydrogen is for rocket, then __________is for MRI. VIEW SOLUTION

• Question 39
  As a matter of convention, an anticlockwise moment is taken as __________ and a clockwise moment is taken as __________. VIEW SOLUTION

• Question 40
  Fill in the blanks :
  (a) Potential difference : Voltmeter then current : __________.
  (b) Hydro Power Plant : Conventional source of energy then solar energy : __________. VIEW SOLUTION

• Question 41
  Correct the mistakes, if any in the following statements :
  (a) A good source of energy would be one which would do small amount of work per unit volume of mass.
  (b) Any source of energy we use to do work is consumed and can be used again. VIEW SOLUTION

• Question 42
  Fuse wire is made up of an alloy of __________ which has high resistance and __________ melting point. VIEW SOLUTION

• Question 43
  The ray diagram shown below is introduced to show how a concave mirror forms an image of an object :
  
  
  
  (a) Identify the mistake and draw the correct ray diagram.
  (b) Write the justifications for your corrections. VIEW SOLUTION

• Question 44
  In traffic signals __________ colour light is used to stop vehicles because it is having __________ wave length. VIEW SOLUTION

• Question 45
  Correct the mistakes, if any in the following statements :
  (a) Magnetic field is a quantity that has magnitude only.
  (b) The magnetic field lines emerge from the south pole and merge at the north pole. VIEW SOLUTION

• Question 46
  Human evolution has a record of changes for the past 15 million years.
  (a) Name the different species of mankind in chronological order from primitive to modern man.
  (b) When were the primitive caves developed?
  (c) Narrate the life led by early man like hominids. VIEW SOLUTION

• Question 47
  There is a widespread outbreak of malaria in your area :
  (a) Suggest some controlling measures to the local authorities concerned.
  (b) Pick out the right symptom for malaria.

  (chill and shiver, and a rise in temperature, diarrohoea)

  VIEW SOLUTION

• Question 48
  Write the two events involved in the sexual reproduction of flowering plants :
  (a) Discuss the first event and write the types.
  (b) Give advantages and disadvantages of that event. VIEW SOLUTION

• Question 49
  In your area there is scarcity of water and due to this people are affected. So, what are the measures to be taken by you to meet out the scarcity of water? VIEW SOLUTION

• Question 50
  Calculate the number of moles in :
  (a) 3.0115 × 10²³ atoms of copper.
  (b) 27.95 g of iron.
  (c) 1.51 × 10²³ molecules of CO₂. VIEW SOLUTION

• Question 51
  Write the common name and IUPAC name of the following :
  
  (a) CH₃CH₂CHO
  
  (b) CH₃COCH₃
  
  (c) $\begin{array}{ccccc}{\mathrm{CH}}_{\mathrm{3}}& –& \mathrm{CH}& –& {\mathrm{CH}}_{\mathrm{3}}\\ & & |& & \\ & & \mathrm{OH}& & \end{array}$
  
  (d) CH₃COOH
  
  (e) HCHO VIEW SOLUTION

• Question 52
  (a) Newton's first law of motion gives a qualitative definition of force. Justify.
   
  
  (b)
   

  The figure represents two bodies of masses 10 kg and 20 kg and moving with an initial velocity of 10 ms^–1 and 5 ms^–1, respectively. They are colliding with each other. After collision, they are moving with velocities 12 ms^–1, 4 ms^–1, respectively. The time of collision is 2 s. Then calculate F₁ and F₂.

  VIEW SOLUTION

• Question 53
  Label the following in the diagram given below :
  (a) Incident ray
  (b) Refracted ray
  (c) Emergent ray
  (d) Angle of refraction
  (e) Angle of deviation
  (f) Angle of emergence
  
  VIEW SOLUTION