SCIENCE AND TECHNOLOGY PAPER B

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. The Chemical formula of POP is _____________ (2CaSO₄H₂O)

2. Magnetic lines of force are __________ where the magnetic field is strong. (crowded)

(ii) Complete the analogy. (2 Marks)

1. CuCl₂ + 2KI → CuI₂ +2KCl : Double displacement ∷ Zn + 2HCl → ZnCl₂ + H₂ : _____________ (Displacement Reaction)

2. Tungsten : Conductor ∷ Ebonite : _____________ (Insulator)

(iii)Name the following : (1)

The quantity expressed in coulomb.

(Electric  charge)

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

1. The second period contains ___________ elements.

a. 8

b. 2

c. 18

d. 32

2. Eucalyptus oil is known as __________

a. natural  indicator

b. olfactory indicator

c. synthetic indicator

d. universal indicator.

3. If a P.D.  of 12 V is applied across a 3 Ω resistor, then the current passing through it is _______

a. 36 A

b. 4A

c. 0.25A

d. 15A

4. When an object is placed between the focus and centre of curvature of a concave mirror, then 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

5. In dispersion of sunlight by a glass prism, ____________ ray is deviated the least.

a. red

b. yellow

c. green

d. violet

2. Attempt the following. (10 Marks)

1. Non-metallic character increases across a period.

2. What is corrosion? Do gold ornaments corrode? Justify.

3. Baking powder is used in preparation of cakes and breads in bakery industry. Give Scientific Reasons. 

4. Distinguish Between: Homologous organs Analogous organs

5.  Draw ray Diagram of Object at infinity for a concave mirror

6.  Explain the propagation of a ray of light, when it travels from rarer to denser medium.

 3. Attempt the following (Any 5) . (15 Marks)

1. Write Short Notes on: Eutrophication

2. Give scientific reasons: Planets do not twinkle

3. Distinguish between: Asexual reproduction & Sexual reproduction

4. What are indicators?

5. Formation of a compound is a chemical change.

6. Why is atomic number said to be a fundamental property?

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

    1.  What would happen if 

      (a) a few drops of strongly smelling eucalyptus oil was treated with vinegar.
      (b) the rain water mixing with river water was found to be having pH less than 7. 
      (c) sonal brushes her teeth with the best quality toothpaste everyday. 
      (d) electrolysis is carried out on sodium chloride solution. (e) copper sulphate is heated.

2. Explain the zig-zag line in the periodic table.

Section B

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

1. Organisms that depend on other organisms for their food are called autotrophic organisms.

Ans. False: Organisms that depend on other organisms for their food are heterotrophic organisms.

2. Proteins are the body building nutrients.

Ans. True.

3. The resemblances and the differences are due to heredity.

Ans. True.

4. Multiple fission is carried out only during favourable period.

Ans. False: Multiple fission is carried out only during unfavourable period.

5. Covalent compounds are soluble in organic solvents.

Ans. True.

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

1. The division of cytoplasm through ________ plane is called simple binary fission.

a. transverse

b. longitudinal

c. any

d. diagonal

2. __________ is a metalloid.

a. Aluminium

b. Antimony

c. Zinc

d, Mercury

3. Organs which are fundamentally the same in structure, but modified for widely different functions are called known as _______ organs.

a. analogous

b. homologous

c. vestigial

d. functionless

4. __________ is the stalk of anther.

a. Stamen

b. Ovule

c. Filament

d. Style

5. Muscle cells contain special type of ______ which are capable of bringing about change in their shape.

a. starch

b. protein

c. fat

d. salt

6. Attempt the following. (10 Marks)

1. Give Scientific reston: Ionic compounds have high melting and boiling points

2. Mention one provision on environment given in our constitution.

3. Draw Neat Labelled Diagram of : Spore formation in Mucor.

4. Distinguish between Detergents V/s Soaps

5. Define : Homoeostasis.

6. Short Notes on : Autotrophic nutrition.

7. Attempt the following. (10 Marks)

1. Draw neat and labelled diagram. Human excretory sytem [Diagram]

2. Give Scientific Reasons: Electrolysis of active metals like Na, K, Al is not carried out by using aqueous solution of their chloride.

3. What would be the consequences of deficiency of haemoglobin in the human body?

4 . State the characteristic features of living organisms. Which characteristic feature is less conspicuous in plants ?

5. Write three measures to conserve water.

6. What is respiration ? Explain the phases of respiration.

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

1. An element X on reacting with oxygen forms an oxide X₂O. This oxide dissolves in water and turns red litmus blue. State whether element X is a metal or a non – metal. Explain with proper example.

2. Write any one uses of each of the following: 

Bleaching powder.

Plaster of Paris.

Alum

Blue vitriol