CBSE Guess > Papers > Important Questions > Class X > 2010 > Science > Science By Shubham CBSE CLASS X Q. 1. What is the least distance of distinct vision of a normal human eyes? Q. 2. Define power of accommodation? Q. 3. What is the type of lens used for correcting myopaia (short sightedness)? Q. 4. What is cataract? Q. 5. What do you mean by angle or deviation in prisim? Q. 6. What do you mean by scattering light or tyndall effect? Q. 7. Why does the sky appear dark instead of blue to an astronaut. Q. 8. What is presbyopia? Q. 9. How do us see colours? Q. 10. What is meant by the far point, near point and the least distance distinct vision? Q. 11. Why does it take some time to see to see object in a dim room when you enter the room from bright sunlight outside? Q. 12. A person with a defective eye-vision is unable to see the object nearer than 1.5m. He wants to read books at distance of 30 cm. Find the nature, focal length and power of the lens he needs in his spectacles? Q. 13. Why do the planets not appear twinkling like the stars? Q. 14. Why does the colour of sky appear blue? Q. 15. Why do the colour of sun appears red at sun-rise and sun-set? Q. 16. What is meant by saying that “potential difference between two points is one v (volt)”? Q. 17. Why are copper and aluminium wires usually used for electricity transmission? Q. 18. Why is an ammeter likely to be burnt out if you connect in parallel? Q. 19.
Q. 20. A 40 watt lamp requires 0.182a of current at 220 volts, while a 6o watt lamp requires 0.272a of current at 220 volts line, how many amperes of current will flow through each lamp? Q. 21. Derive the formula for the heat generated by an electric current? Q. 22. Define and explain ohm’s law? Q. 23. Define electric power. Write s.i unit of electric power. Define it also. Derive the formula for electric power. Q. 24. Why are coils of electeric toasters and electric irons made of an alloy rather than a pure metal? Paper By Shubham |
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