### Science and Technology July 2015 Board Paper

SCIENCE JULY 2015 PAPER ONE

NOTE: (i) Draw well - labelled diagrams wherever necessary.
(ii) All questions are compulsory.
(iii) Students should write the answers of questions in sequence.

Q. 1. A. (1) Fill in the blanks 

(1) Very fine particles mainly scatter _____________ light. (blue)

(2) 1 mA = __________________ A.  (10-3A)

(2) Match the column ‘A’ with column ‘B’. 
 Column ‘A’ Column ‘B’ (1) Eka - boron (a) Germanium (2) Eka - Aluminium (b) Scandium (3) Eka - Silicon (c) Gallium

(B) Choose the correct alternative and rewrite the following: 

(1) Mirror used by a dental surgeon is ______________.
(a) plane
(b) convex
(c) concave
(d) convex and concave

(2) What will happen to the curent passing through a resistance, if the potential difference across it is doubled and the resistance is halved?
(a) remains unchanged
(b) becomes double
(c) becomes half
(d) becomes four times

(3) You are given three equal resistances. In how many combinations can they be arranged?

(a) Three
(b) Four
(c) Five
(d) Two

(4) Inside water, an air bubble behaves _______.
(a) always like a flat plate
(b) always like a concave lens
(c) always like a convex lens
(d) always like a concave mirror

(5) A glass slab is placed in the path of convergent light. The point of convergence of light
(a) moves away from slab
(b) moves towards the slab
(c) remains at the same point
(d) undergoes lateral shift

Q. II. Answer the following questions. (any five)  [5 x 2 = 10]

i. State Dobereiner’s Triads giving one example.

ii. Edible oil is not allowed to stand for a long time in an iron or tin container. Give reasons.

iii. An electric iron rated 750 W is operated for 2 hours/day. How much energy is consumed by the electric iron for 30 days?

iv. Differentiate between conductors and insulators (any two points).

v. Give four uses of sodium carbonate (washing soda).

vi. Draw a labelled diagram: Dispersion of light through a prism.

Q. III. Answer the following questions. (any five): [5 x 3 = 15]

i. If sodium chloride is added to silver nitrate solution:
a. which precipitate is formed?
b. name the type of reaction.
c. write the chemical equation.

ii. Define:
a. Chemical combination reaction
b. Endothermic reaction
c. Oxidation reaction

iii. Give the uses of a concave mirror.

iv. Name any six domestic appliances based on the heating effect of electric current.

v. Explain: ‘How is a rainbow formed’?

vi. If an object is placed in front of a convex lens beyond 2F1, then what will be the position, relative size and nature of an image which is formed? Explain with a ray diagram.

Q. IV. Answer any one of the following questions: 

i. Explain ‘Electric generator’ with the help of the following points:
a. Diagram of an AC Generator with labelling
b. Principle of an electric generator
c. Function of slip rings
d. Any two uses of a generator.

ii. Write about the sources of noise pollution. Give the impact of noise pollution on human body.

SCIENCE JULY 2015 PAPER TWO

Q. 1. A. (1) Fill in the blanks: 

(1) ______________ is a greenish coloured poisonous gas. (Chlorine)

(2) Compound with identical molecular formulae but different structures, are called _____________ (isomers)

(2) Name the following: (1)

Cells that assist the neurons in their function.
Ans. The neuroglia are supportive cells that assist the neurons in their functions.

(3) Match the following: 
 Column ‘I’ Column ‘II’ (1) Inhibits plant growth (a) Breaks large fat globules into smaller ones (2) Cytokinins (b) Auxins (3) Cellular respiration (c) Mitochondria (4) Bile (d) Promote cell division (e) Abscisic acid

(B) Choose the correct alternative and rewrite the following: 

(1) Which gas is released in plants during the process of photosynthesis?

(a) Carbon dioxide
(b) Oxygen
(c) Nitrogen
(d) Hydrogen

(2) To observe the hydro and clearly, Raju should see it first under the low power lens and then under the high power lens in order to see _____________

(a) less area
(b) wide area
(c) more buds
(d) all of the above

(3) Reaction of iron nails whith copper sulphate solution is an example of _____________________

(a) combination reaction
(b) decomposition reaction
(c) displacement reaction
(d) double displacement reaction.

(4) Which of the following is lue in colour?

(a) CuSO4
(b) FeSO4
(c) ZnSO4
(d) Al2 (SO4)3

(5) Acetic acid _______________
(a) turns blue litmus red
(b) in insoluble in water
(c) is pale yellow in colour
(d) turns red litmus blue

2. Answer the following questions (any five): [10 Marks]

i. Calcium floats over water during the reaction with water. Give reason.

ii. Differentiate between: Toilet soap and Laundry soap.

iii. How do plants get rid of their excretory products?

iv. Draw a well-labelled diagram of a Neuron.

v. Write a short note on regeneration.

vi. What do you mean by ‘Connecting Links’? Give one example.

3. Answer the following questions (any five): 

i. Explain Mendel’s Monohybrid cross. Give an example.

ii. Draw a diagram which shows sex determination in man.

iii. a. What do you mean by seismonastic movement?

b. Name the types of movements in plants. Give one example of each movement.

iv. If the electronic configuration of metal A is (2, 8, 1) and that of metal B is (2, 8, 2) then:

a. Which metal is less reactive?

b. Write the names of the two metals.

c. Write the balanced chemical equation of reaction of any one metal with hydrochloric acid.

v. What are Allotropes? Name any two allotropic forms of carbon. Give one use of it.

vi. a. By which process do green plants synthesize their food?

b. Name the factors which take part in this process. c. Write the chemical equation of the above process.

4. Answer the following question (any one): 

i. Name the organs of the human male reproductive system and state the functions of any two organs.

ii. State the functions of the Maharashtra Pollution Control Board.  