(Important Questions) Important Question For CBSE Class X Science Board Examination 2009-10 (Set -12)

Q. 201. What is the length and diameter of each chromosome?

Q. 202. What is nucleolar organizer region?

Q. 203. Which purine nitrogen bases are present in the DNA molecule?

Q. 204. Which is the complimentary base pair of  Cytosine?

Q. 205. What is the distance between each nucleotide pair in a DNA strand?

Q. 206. In which animal, the embryo develops into a female at high temperature?

Q. 207. What does the Recapitulation theory of Ernst Haeckel state?

Q. 208. Who is known as the Father of Taxonomy?

Q. 209. What is retrovirus? Give an example.

Q. 210. What is the extra chromosome found in male insects called?

Q. 211. How do CFC’s harm the atmosphere?

Q. 212. For what purpose are wet scrubbers used?

Q. 213. What is Eutrophication?

Q. 214. Why is the BOD of potable water less?

Q. 215. What is the full form of NEERI?

Q. 216. Define 1 A current.

Q. 217. What symbol is used in an electrical circuit to show inductor?

Q. 218. Comment on the voltage drop across a series connection.

Q. 219. Is it advisable to connect appliances in series connection domestically? Justify your answer.

Q. 220. 1 volt ampere is how many kW?

Q. 221. What is the nature and size of image formed by a convex lens when the object is at 2F?

Q. 222.What is the function of ciliary muscles?

Q. 223.Why is a voltmeter always connected in parallel in an electrical circuit?

Q. 224.A lamp of 100W glows for 2 hrs daily. Calculate the energy consumed in 30 days.

Q. 225. Define electroplating.

Q. 226. Name two addition and two condensation polymers.

Q. 227. What is the wavelength of visible light?

Q. 228. Where in Gujarat are wind farms located?

Q. 229. From which places is geothermal energy obtained in Gujarat?

Q. 230. What is the carbon content in anthracite?

Q. 231. Give two uses of Coke.

Q. 232. What gas is added in LPG cylinders to detect any leakage?

Q. 233. Which power station in Gujarat uses natural gas as a fuel?

Q. 234. What is the calorific value of hydrogen?

Q. 235. Which substances are used as coolants in nuclear reactors?

Q. 236. Name the moons of Saturn.

Q. 237. What are asteroids composed of?

Q. 238. How far is sun located from the galactic centre?

Q. 239. Which type of stars is found mostly in elliptical galaxies?

Q. 240. Give two properties of Rocket fuel.

Q. 241. What is the calorific vale of biogas?

Q. 242. Write the full form of GSLV.

Q. 243. Which satellite is used for weather forecasting?

Q. 244. What needs to be retrieved in Solvay’s ammonia soda process?

Q. 245. Which compound is used as an antacid?

Q. 246. Write the equation of the reaction taking place on inert anode in the electrolysis of molten NaCl.

Q. 247. Why is hydrogen used in welding metals?

Q. 248. At what temperature is rubber heated with sulphur to get vulcanized rubber?

Q. 249. What is the function of hepatic caecae found is digestive system of grasshopper?

Q. 250. During fission process what are the respective atomic masses of the elements obtained?