Kendriya Vidyalaya, Sikar
MM: 40 Date 19.01.13 Time duration: 90 mins
Section A (Physics)
Q1. A convex lens of focal length 30cm is combined with a concave lens of focal length 30cm. What is the power of the combined lens?(1)
Q2. The following table gives the valves of the speed of light of a few media
S.No. 1 2 3
Medium Air or vaccum Water Glass
Speed 3X108m/s 2.25X108m/s 2X108m/s
Which of the medium has highest optical density and why? (2)
Q3. When an object is placed at a distance of 60cm from a convex mirror the magnification produced is 1/2. Where should the object be placed to get a magnification of 1/3. (3)
Q4. State two main causes of the person developing for sightedness with the help of ray diagram. Suggest how he can be helped to overcome this ability. (3)
Q5. Explain why- (3)
- Danger signals are red.
- Sun appears red during sunrise or sunset.
- The printed letters appears to be raised when a glass slab is placed over it.
Q6. a. Name the mirror which is used as a shaving mirror. (2)
b. Name the mirror used as a rear view mirror in vehicle.
c. Name the lens which always form an errect image.
d. Name the mirror which shows the property of lateral inversion.
Section B (Chemistry)
Q7. What is a Homologous series? Explain with an example. (2+1)
Q8. What will be formula and electron dot structures of following compounds: (4)
a.Carbon di oxide b. Methane c. Ethyl Alcohol d. Ethanoic Acid
Q9. Why soaps can not be used in hard water? (2)
Q10. a. Write chemical equation of Saponification and Esterification reactions. (2)
b. Draw and explain the structure of the Micelle. (2)
Section C (Biology)
Q11. Which plant was choosen by Mendel for his experiments?Write its scientific name. (1/2+ 1/2)
Q12. Which contraceptive device is also effective in stopping STDs.(1)
Q13. What is the role of Endosperm in flowering plants? (1)
Q14. Explain the meaning of Dominant and Recessive characters. (2)
Q15. Give flow chart of Sex determination in humans. (2)
Q16. Explain Spore formation in bread mould as mode of reproduction. (3)
Q17. Explain why the sexual reproduction is better mode of reproduction than the asexual reproduction? (3)