# Hydroelectricity and Convex Lens Position

Topics: Hydroelectricity, Tidal power, World energy resources and consumption Pages: 2 (416 words) Published: December 28, 2012
Iron reacts with cone HCl and Conc.H2SO4 acids. But, it does not react with Conc.HNO3. Why?

Diamond is the hardest allotrope of carbon. Give reason for its hardness.

Differentiate mass and weight.

(A) Assertion : Liquid nitrogen is the most commonly used element in cryogenics. (R) Reason : It is not legally purchaseable around the world. Write
(i) Both (A) and (R) are correct
(ii) (A) is wrong but (R) is correct
(iii) Both (A) and (R) are wrong
(iv) (A) is correct but (R) is wrong

Draw this diagram and label the parts.

In the list of non conventional sources of energy given below, some of them are wrong. List out the wrong ones.
(wind energy, solar energy, hydro electric power, nuclear energy, tidal energy, wave energy, geo thermal energy)

Draw the schematic diagram of an electric circuit consisting of a battery of two cells of 1.5V each, three resistance of 5ohm, 10ohm and 15ohm respectively and a plug key, all connected in series.

Match the following in the case of a convex lens
Position of the object Relative size of the image
(a) Beyond 2F −infinitive large
(b) At 2F −diminished
(c) Between F and 2F −same size
(d) At focus F −enlarged

A concave lens has focal length of 15cm. At what distance should the object from the lens be placed, so that it forms an image 10cm from the lens?

Fill in the blanks:
(a) For a motor: a permanent magnet, then commercial motor ___________. (b) Focal length of a lens: meter, then for power of a lens ____________

SECTION :III

(a) Suggest some controlling measures to the local authorities concerned. (b) Pick out the right symptom for malaria.
(chill and shiver and a rise in temperature, diarrhoea)

PART −B

Write the two events involved in the sexual reproduction flowering plants. (a) Discuss the first event and write the types.