Question

CHENNAI DISTRICT
SCIENCE-UNIT TEST.
STD: 10
TIME:1.30 HS
MAX MARKS:50
(UNIT 2.3.8.0.14)
PARTI
CHOOSE THE CORRECT ANSWER:
(9xts)
1. Where should an object be placed so that a real and inverted Image of same size is obtained by a
Convex lens
a) bjm chinfinity d)between fand 21
2. The eye defect "Presbyopia' can be corrected by
a)Convex les b)Concave lens c)Convex mirror d)Bifocal lenses
3.The value of Rragadro number
a)6.023x10 b)6.023x11010.623x10" d)6.023x10
4. The process of coating the surface of metal with a thin layer of zinc is called
a)Painting b]Thinning c)Galvanization Electroplating
5. The number of periods and groups in the periodic table are_
a)6,16 67,17 c)8,18 d)7,18
6.Solubiyty of Nac in 100ml water is 36g. If 25g of salt is dissolved in 100ml of water how much
more sit required for saturation
a}126 b)118 c)168 d)20 €
7.'Heart of Heart' is called
a) (A node b)AV node c)Purkinje fibres d)Bundle of His
_involves evaporative loss of water from aerial parts.
a)Transpiration b)Osmosis c)
Respiration d)None of the above
9. Which of the following process requires energy?
a}Active transport b)diffusion c)Osmosis d)All of them
PART-11
NOTE: ANSWER ANY FOUR (4)QUESTIONS ONLY. (Qn.11 IS COMPULSORY) (4x2-8)
10.State Snell's Law.
11.Draw a ray diagram to show the image formed by a Convex lens when the object is placed
between F and 2F.
12.What is rust? Write the chemical formula of rust?
13. What causes the opening and closing of guard cells of stomata during transpiration?
14. What is the importance of valves in the heart?

Answer 1

Answer:

2CMassage I will try it on the computer but please let me as brainlist and the other guys have a way of getting my own stuff from decimal and then to