(b) How does a universal indicator work? (c) Water is a neutral substance. What colour will you get when you add a few drops of universal indicator to a test-tube containing water?
16. State the functions of the following hormones: (a) Thyroxin (b) Adrenaline (c) Growth hormone
17. (a) Draw a simple diagram of the human eye and label clearly the cornea, iris, pupil, ciliary muscles, eyelens, retina, optic nerve and blind spot. (b) Describe the working of the human eye with the help of the above diagram. (e) How does the eye adjust itself to deal with light of varying intensity?
18. In one of the industrial processes used for manufacture of sodium hydroxide, a gas X is formed as by product. The gas X reacts with lime. water to give a compound Y which is used as a bleaching agent in chemical industry. Identify X and Y giving the chemical equation of the reactions involved.
19. What are the scientific names for the following receptors in animals? (a) receptors for light (b) receptors for heat (c) receptors for sound (d) receptors for smell (e) receptors for taste
20. What is the difference in colours of the Sun observed during sunrise/sunset and noon? Give explanation for each. OR Five solutions A,B,C,D and E when tested with universal indicator showed pH as 4,1,11,7 and 9, respectively. Which solution is (a) neutral? (b) strongly alkaline? (c) strongly acidic? (d) weakly acidic? (e) weakly alkaline? Arrange the pH in increasing order of hydrogen-ion concentration.
21. (a) Name the three of nerves which constitute the peripheral nervous system. (b) What is the difference between a reflex action and walking ? (c) How do we detect the smell of an incense stick (agarbatti)?
22. When do we consider a person to be myopic or hypermetropic? Explain using diagrams how the defects associated with myopic and hypermetropic eye can be corrected?
23. A white shirt has a yellow stain of curry. When soap is rubbed on this shirt during washing, the yellow stain turns reddish-brown. On rinsing the shirt with plenty of water, the reddish-brown stain turns yellow again.. (a) Name the natural indicator present in curry stain. (b) Explain the changes in colour of this indicator which take place during washing and rinsing the shirt. 3 3 3 3 3 3 5 5 Page 3 of 4 (c) What is the nature of soap (acidic/basic) as shown by the indicator present in curry stain?
OR
What is the function of receptors in our body? Think of situations where receptors do not work properly. What problems are likely to arise?
24. (a) Describe an activity along with a labelled diagram the phenomenon of dispersion through a prism. (b) Explain in brief the formation of rainbow with the help of figure.
plz answer itt
of pic nd of written
16. State the functions of the following hormones: (a) Thyroxin (b) Adrenaline (c) Growth hormone
17. (a) Draw a simple diagram of the human eye and label clearly the cornea, iris, pupil, ciliary muscles, eyelens, retina, optic nerve and blind spot. (b) Describe the working of the human eye with the help of the above diagram. (e) How does the eye adjust itself to deal with light of varying intensity?
18. In one of the industrial processes used for manufacture of sodium hydroxide, a gas X is formed as by product. The gas X reacts with lime. water to give a compound Y which is used as a bleaching agent in chemical industry. Identify X and Y giving the chemical equation of the reactions involved.
19. What are the scientific names for the following receptors in animals? (a) receptors for light (b) receptors for heat (c) receptors for sound (d) receptors for smell (e) receptors for taste
20. What is the difference in colours of the Sun observed during sunrise/sunset and noon? Give explanation for each. OR Five solutions A,B,C,D and E when tested with universal indicator showed pH as 4,1,11,7 and 9, respectively. Which solution is (a) neutral? (b) strongly alkaline? (c) strongly acidic? (d) weakly acidic? (e) weakly alkaline? Arrange the pH in increasing order of hydrogen-ion concentration.
21. (a) Name the three of nerves which constitute the peripheral nervous system. (b) What is the difference between a reflex action and walking ? (c) How do we detect the smell of an incense stick (agarbatti)?
22. When do we consider a person to be myopic or hypermetropic? Explain using diagrams how the defects associated with myopic and hypermetropic eye can be corrected?
23. A white shirt has a yellow stain of curry. When soap is rubbed on this shirt during washing, the yellow stain turns reddish-brown. On rinsing the shirt with plenty of water, the reddish-brown stain turns yellow again.. (a) Name the natural indicator present in curry stain. (b) Explain the changes in colour of this indicator which take place during washing and rinsing the shirt. 3 3 3 3 3 3 5 5 Page 3 of 4 (c) What is the nature of soap (acidic/basic) as shown by the indicator present in curry stain?
OR
What is the function of receptors in our body? Think of situations where receptors do not work properly. What problems are likely to arise?
24. (a) Describe an activity along with a labelled diagram the phenomenon of dispersion through a prism. (b) Explain in brief the formation of rainbow with the help of figure.
plz answer itt
of pic nd of written
Answers & Comments
Answer:
b) ans universal indicator changes colour in different pH environments. At low pH, it appears red, and at high pH, it appears blue or violet.