Science Paper Two

Time : 3 hours        Max Marks: 80

SECTION 'A'

1. (A) Answer the following. (5)

(i) Fill in the blanks and rewrite the completed statements:. (2 Marks)

1. Elements showing properties of both metals and non – metals are known as ________ (metalloids)

2. The chemical reactions in which heat is liberated are called ________ reactions. (exothermic)

(ii) Complete the analogy. (2 Marks)

1. Glass : Insulator ∷ Copper : __________ (Conductor)

2. CuI₂ : Brown ∷ AgCl : ________ (White)

(iii) Find the odd one out: (1 Marks)

Loudspeaker, Microphone, Electric motor, Bar Magnet.

Ans. Bar magnet.

 (B) Rewrite the following statements by selecting the correct  options: (5 Marks)

1. The modern periodic table is based on ________

a. the principle of octaves

b. the atomic number of elements

c. the atomic mass of elements

d. the presence of traids of elements

2. The colour of phenolphthalein indicator in  a basic solution is _______

a. yellow

b. green

c. orange

d. pink

3. 1 kilowatt hour = _______

a. 4.6 × 10⁶ joules

b. 3.5 × 10⁶ joules

c. 30.6 × 10⁶ joules

d. 3.6 × 10⁶ joules

4. The apparent depth of swimming pool is ________ the real depth.

a. less than

b. greater than

c. equal to

d. half

5. When an object is placed at the centre of curvature of a concave mirror, the image formed is _________

a. real and magnified

b. virtual and magnified

c. real and of the same size as that of the object.

d. virtual and of the same size as that of the object.

2. Attempt the following. (10 Marks)

1. Give Scientific Reason: Non-metallic character increases across a period.

2. Give Scientific Reason: Formation of a compound is a chemical change.

3. State application (uses) of baking soda

4. Explain the working of electric fuse.

5. Distinguish Between: Electric Motor V/s Electric Generator.

3. Attempt any 5 of the following. (15 Marks)

1.   Explain how the formation of rainbow occurs.

2. What is ray diagram? What are the rules used for drawing ray diagram for the formation of image by spherical mirror.

3. What is short circuiting ?

4. How are electrical appliances connected at home ? Why ?

5. Write the uses of washing soda.

6. Explain the following terms

Rancidity, Endothermic Reactions,

Q4. Attempt the following (any 1) ( 5 marks)

1. How do you calculate valency of an element from its electronic configuration ?

2. Take finely powdered Zinc and allow it to react with CuSO4 solution. Then take Zinc granules and carry out the same reaction. Which reaction will take place faster and why?

Section B

5. (A) Say true or false with reason (5 Marks)

1. The middle part of sperm possesses _______ which produce energy.  (mitochondria)

2. In _______ mode of reproduction the offsprings are with minor differences. (asexual)

3. The organic compounds having double or triple bonds in them are termed as _______ (unsaturated hydrocarbons)

4.The digested food is absorbed by the _______ in the small intestine. (villi)

5. Mercury and _______ are two metals in the liquid state at room temperature. ( gallium)

5. (B) Rewrite the following statements by selecting the correct  options: (5 Marks)

1. _________ is an ore of aluminium.

a. Cryolite

b. Bauxite

c. Haematite

d. Aluminium carbonate

2. Bronze in an alloy of ______

a. copper and tin

b. copper and iron

c. copper and zinc

d. copper and aluminium .

3. The reaction of ethene with bromine is ________

a. a substitution reaction.

b. an addition reaction.

c. an elimination reaction.

d. an oxidation reaction.

4. The unutilized carbohydrates are stored in the form of ________ in plants.

a. proteins

b. fats

c. glycogen

d. starch

5. The ____ provides general basic design of the body.

a. inheritance

b. father

c. mother

d. evolution.

6. Attempt the following. (10 Marks)

1. What happens: When steam is passed over aluminium.

2. Explain: What do you understand by substitution reaction?

  

 3. Draw neat and well labelled diagram of  Reflex arc. [Diagram]

 4. Describe the modes of reproduction in unicellular organisms.

5. What are the different laws to prevent pollution?

7. Attempt the any five following. (15 Marks)

1. Write short notes on: Narmada Bachao Andolan

 2. Distinguish between: Multiple fission and Regeneration

3. What is an alloy? Give two examples with their chemical composition.

  

4 . State and explain how alkanes are further classified.Ans.

5. How are fats digested in the human body?

 6. Write short notes on: Pollination

 8. Attempt the following (any 1) (5 marks.)

1. Darwin's theory of evolution.

2. Explain the process of translocation in plants.