10th Science Periodic Test I A (2018-19)
Time: 1.5 hour
Subject code: 086
All questions are compulsory
Question: 1. What will happen to a plant if its xylem is removed? (1)
Question: 2.What do you mean by precipitation reactions? Explain giving example. (1)
Question: 3. What happens to the image distance in the eye when we increase the distance of an object from the eye? Why? (1)
Question: 4. Explain the reddish appearance of sun at sunrise and sunset. (2)
Question: 5. The absolute refractive indices of two media ‘A’ and ‘B’ are 2 and 1.5 respectively. If the speed of light in medium ‘B’ is 2×102m/s, calculate the speed of light in (2)
- Medium ‘A’.
Question: 6. What is ascent of sap? (2)
Question: 7.Translate the following statements into chemical equations and balance them: (2)
- Copper (II) burns in the presence of oxygen gas to form copper oxide.
- Silver nitrate reacts with sodium chloride to form silver chloride and sodium nitrate.
Question: 8. Quicklime when dissolved in water gives compound ‘A’ which is used in white-washing. Compound A reacts with CO2 to form a white colored compound of ‘B’. Identify A and B. Also write balance equation involved in the conversion of A to B. (2)
Question: 9. Mention the major events during photosynthesis. (3)
Question: 10. Two solutions X and Y have pH values of 3.0 and respectively. (1+2)
- Which of these will turn phenolphthalein solution to pink?
- Write any 2 applications of pH in our daily life and explain them.
Question: 11. Give reasons: (3)
- Plants look preen.
- Nutrition is necessary for an organism.
- We boil the leaf in alcohol when we are testing it for starch.
Question: 12. A 2 cm high object is placed at a distance of 32 cm from a converging mirror. The image is real and 3 cm in size. Find the focal length of the mirror and the position and nature of the image formed? (3)
Question: 13 (3+2)
- What is myopia? Write a cause for the development of this defect. With the help of ray diagrams, show the defect and how it can be correct using spectacles having appropriate lens.
- What do you understand by dispersion of light? Which of the following show dispersion of light: rectangular glass slab of glass prism, and why?
Question: 14. (2+3)
1. Define double circulation.
2. Trace the path of blood circulation in humans.
Question: 15. Answer the following question: (2+2+1)
- Distinguish between acids and bases on the basis of their reactions with metal carbonates and write balanced equations to support your answer.
- Why does distilled water not conduct electricity, whereas rain water does?
- What are olfactory indicators?