Neo Convent Sr

NEO CONVENT SR. SEC. SCHOOL, PASCHIM VIHAR

SCIENCE AND TECHNOLOGY - iX

UT- 2 (04-08-2017)

TIME: 3hrs MM:80

General instruction:

(a) All questions are compulsory.

(b) Diagrams should be made with pencil and it is properly labelled (wherever it is required).

(c) Avoid excessive cuttings in your paper it will lead to deduction of marks.

(d) If paper is not visible/clear ask for different paper.

SECTION A (1 MARK )

1. Which organelle is known as the powerhouse of the cell? Why?

Ans. Mitochondria is known as the powerhouse of the cell because they produce energy in the form of

ATP.

2. Define Newton’s second law of motion and derive the formula of force?

Ans. Newton’s second law of motion states that rate of change of momentum is directly proportional to applied force and takes place in the direction in which the force acts.

Formula of force i.e F = ma

3. Why the passengers tends to fall forward when the bus stops suddenly?

Ans. In a running bus, our speed is equal to the speed of bus. As a moving bus stops, the lower part of the

body being in contact with the bus comes to rest, but the upper part due its inertia of motion, remains

in the states of motion .Hence we fall in the forward direction.

4. Why the athletes are provided with a cushion or a heap of sand to fall upon during high jump.

Ans. This is done to prevent injury to the athlete when he falls down after making a high jump as a

cushion or a heap of sand reduces the athletes momentum more gently.

5. If abottle of perfumeis opened in one corner of a room, it immediately spreads throughout theroom. Why?

Ans. If abottle of perfumeis opened in one corner of a room, it immediately spreads throughout

theroom because the particles of matter are continuously moving.

6. How can you say that mixed cropping and intercropping are advantageous .

Ans. Mixed cropping and intercropping are advantageous because they reduces the chance of crop failure

and enhance the production of crop per unit area.

7. Convert the following temperature to degree Celsius

(i)773K (ii) -333K

Ans. (i) 773 K = 773 - 273 = 5000 C

(ii) -333K = -333 – 273 = -6060C

8. How does the water kept in an earthen pot (matka) become cool during summer?

Ans. An earthen pot has porous wall. When water evaporates from the outer surface of the earthen wall,

it takes the latent heat of vaporisation from the earthen pot and thus causes cooling. As a result, the

temperature of water falls.

9. Name the technique to separate - (a) Salt from sea water (b) Butter from curd.

Ans. (a) Evaporation and crystallization (b) Centifugation

10. Draw a well labelled diagram of neuron.

Ans.

11. What is the physical state of water at

a)0oC?

b)100oC

Ans. (a) At 0oC the physical state of water is solid and liquid.

(b) At 100oC the physical state of water is both liquid and gas.

12. Liquids generally have lower density as compared to solids. But ice floats on water. Why?

Ans. When water is converted into ice, its volume expands about 10 % in comparison to the volume of

water. Thus, ice occupies more space. As a result, its density decreases and it floats on water.

13. Describe the formation of Green manure and vermicomposting.

Ans. Green manure:- Some plant like sun hemp or gaur are grown in the field prior to the sowing of the crop seeds. These are then mulched by ploughing them into the soil.These green plants gradually decompose and turn into green manure which helps in enriching the soil in nitrogen and phosphorus.

Vermicomposting:- It is the compost prepared from organic matter using earthworms which hasten the process of decomposition.

14. (a) What produces more severe burns, boiling water or steam?

Ans. Steam

(b) Which is more effective in cooling ice at 00C or water at 00C.

Ans. Ice at 00C

15. If after 20 rounds trips of radius R, the body returns to its starting point. Calculate the distance covered and its displacement.

Ans. Distance = 40πr , Displacement =0

16. (a)Expand DNA.

Ans. DNA = Deoxyribonucleic acid

(b) Name the functional segment of DNA.

Ans. Genes

17. What are the consequences of the following conditions?

(a) A cell containing higher water concentration than the surrounding medium.

(b) A cell having lower water concentration than the surrounding medium.

Ans. (a) The cell will shrink.

(b)The cell swells up.

18. If you are provided with some vegetables to cook. You generally add salt into the vegetables during cooking process. After adding salt, vegetables release water. What mechanism is responsible for this?

Ans. Osmosis

SECTION B( 2 MARKS)

1. Expand RER and SER. Differentiate between them in structure and function.

Ans.

Rough Endoplasmic Reticulum / Smooth Endoplasmic Reticulum
1.They have ribosomes attached on their surface. / 1.They have do not have ribosomes attached on their surface
2.RER manufactures proteins and transports them to various places. / 2.SER helps in manufacturing lipids and transports them to various places.

2. From a rifle of mass 4 kg, a bullet of mass 50 g is fired with an initial velocity of 35 m s-1. Calculate the initial recoil velocity of the rifle.

Ans. Mass of bullet = 50÷1000 = 0.05 kg

Velocity of bullet = 35 ms-1

Mass of rifle = 4 kg

Putting these values in the relation:

Mass of bullet × velocity of bullet = Mass of gun × Recoil velocity of gun

0.05 × 35 = 4 × Recoil velocity of gun

Recoil velocity of gun = 1.75÷4 = 0.4375 ms-1

3. What is organic farming ? How can you say that it is the best way of farming?

Ans. Organic farming is a farming system in which there is minimal or no use of chemicals like fertilizers, pesticides etc. and there is maximum input of organic manures, recycled farm wastes and bio-agents. It is best way of farming as it help in improving soil structure.

4. Differentiate between evaporation and boiling. Give two points of differences.

Ans.

Evaporation / Boiling
1. It is a surface phenomenon. / 1. It is a bulk phenomenon.
2. It gives cooling effect. / 2. It does not gives cooling effect.

5. Draw a labeled diagram of an animal cell.

Ans.

6. Rahim goes to market to buy mangoes and he travels first half of his journey with a velocity of 10m/s and next half with a velocity of 15m/s. But he finds market is closed due to sealing drive of MCD and he returns back to his home with velocity of 20m/s. Calculate the average speed and average velocity for

(i). home to market

Ans: average velocity == 12 m/s

(ii) home to home in a round trip.

Ans: average velocity = 0 m/s

7. Name the following.

a)Tissue that forms the inner lining of our mouth.

b)Tissue that connects muscle to bone in human.

c)Tissue that transports food in plants.

d)Tissue that stores fat in our body.

Ans. a)Tissue that forms the inner lining of our mouth = Simple squamous epithelium

b)Tissue that connects muscle to bone in human = Tendons

c)Tissue that transports food in plants = phloem

d)Tissue that stores fat in our body = Adipose tissue

8. A solution has been prepared by dissolving 5 g of urea in 95 g of water. What is the mass percent of urea in the solution ?

Ans. Mass of urea = 5 g

Mass of water = 95 g

Mass percentage of urea = 5 %

9. A force of 5 N gives a mass m1, an acceleration of 10 m/s2 & on mass m2, an acceleration of 20 m/s2 , what acceleration would it give if both the masses were tied together?

Ans. (i) In the first case :

F = 5N

Mass = m1

Acceleration a = 10 m/s2

F = m1 × a

m1 = 5 ÷ 10 = 0.5 Kg

(ii) In the second case :

F = 5N

Mass = m2

Acceleration a = 10 m/s2

F = m2 × a

m2 = 5 ÷ 20 = 0.25 Kg

(iii) In the third case :

F = 5N

Mass = m1 + m2 = 0.50 + 0.25 = 0.75 kg

Acceleration a = 10 m/s2

Acceleration = 5 ÷ 0.75 = 6.66 m/s2

10. How will you separate the components of black ink? Explain with the help of a labelled diagram.

Ans. Component of black ink can be separated by evaporation. Or Chromatography.

Fill half a beaker with water put a watch glass on the mouth of the beaker. Put few drops of

ink on the watch glass. Now start heating the mixture. The evaporation of water takes

place. Continue heating till there is no further change on the watch glass water has

evaporated and left behind in the watch glass is dye.

11. Differentiate between broilers and layers . Name the indigenous and exotic breeds of fowl.

Ans. The broiler is a poultry bird specially groomed for obtaining meat and layer is the egg-laying

poultry bird.

Indigenous breed = Aseel , Ghagus , Chittagong , Busra

Exotic breeds = Leghorn

12. a. What type of motion is represented by each of the following graphs?

Ans. A . Uniform retardation

B. Uniform accelration

C.Negative velocity

D. The body is at rest position

13. Complete the following table:

Ans: a) parenchyma b) sclerenchyma c) complex d) phloem

14. A scooter moving at a speed of 10m/s is stopped by applying brakes which produce a uniform acceleration of –0.5 ms-2. How much distance will be covered by the scooter before it stops?

Ans: 100 m

SECTION C( 3 MARKS)

1. Name A,B,C,D,E and F in the following diagram showing change in its state

Ans: A – fusion B- vapourisation C- condensation D- solidification E- sublimation

F- sublimation

2. Describe composite fish culture system. Write any two problems faced in this culture system and give the method to solve this problem.

Ans: In composite fish culture , both local and imported fish species are used in a single pond

Problems - Breed only in monsoon

Solution - Hormonal stimulation

3. Describe three types of muscular tissue with their characteristics.

Ans: Striated - Attached to bone , work according to our will , voluntary , elongated , cylindrical , unbranched , dark and light bands

Unstriated - smooth , involuntary , tapering at both ends

Cardiac - cylindrical , branched , light and dark bands , involuntary , found in heart

4. Derive second and third equation of motion graphically.

Ans. Equation for position – time graph

S= OA X OC + ½ (AD x BD)

S=ut + ½ at^2

Equation for position velocity relation

S= (OA + BC) x OC / 2

S= ( u+ v) t /2

T= (v-u) /a

S= (vu) x (v-u) / 2a

2as = v^2 – u^2

5. A liquid mixture has two liquids A and B. The boiling point of liquid A is 560C and that of liquid B is 700 C. Name the process by which these liquids can be separated. Draw a well labelled diagram of the method.

Ans: Fractional distillation

7 Describe the major cattle farming and poultry farming management practices done for better yield.

Ans: 1) clean and proper shelter

2) supply of balanced food

3) proper sanitation and hygiene

4) Appropriate vaccination

5) Cross breeding program

8 Two football players of opposite teams collide while they are trying to hit a football on the ground and after colliding, they move off together. One with a mass of 60 kg was travelling with a velocity of 5.0 m s-1 and the other footballer with a mass of 55 kg was moving faster with a velocity 6.0 m s-1 towards the first player. What is the direction and the velocity with which they move after they become entangled?

Ans: v= - 0.26 m/s

They move from right to left in direction of second player

9 An 8000 kg engine pulls a train of 5 wagons, each wagon of mass 2000 kg, along a horizontal track. If the engine exerts a force of 40,000N & the track offers a friction force of 5,000 N. Calculate

a) the net accelerating force,

b) the acceleration of the train, and

c) the force of wagon 1 on wagon 2.

Ans: a) F= F 1 + F 2 = 40000 + (- 5000) = 35000 N

b) a= 3.5 m/ s2

c) F= 28000 N

MCQ (10 MARKS)

1. SI unit of force is

(a) kg m/s.

(b) Newton.

(d) None of these.

2. A canon after firing recoils due to

(a) Conservation of energy.

(b) Backward thrust of gases.

(d) Newton’s first law of motion.

3. A rocket or jet engine works on the principle of

(a) Conservation of energy

(b) Conservation of momentum

(d) Newton’s third law of motion.

4. SI unit of temperature is

(a) 0F (b) 0C (c) K (d) none

5. Heat is liberated when

(a) Water turns into steam

(b) Ice melts (c) Water is heated (d) Water Vapour Condenses

6. How can 25°C be represented in Kelvin scale

(a) 273.15K (b) 298.15K

( c) 330K (d) 220K

7. How can O K be represented on Celsius scale:

(a) -273.15°C (b) 298.15°C

8. Ribosomes are the center for –

(a) Respiration (b) Photosynthesis (c) Protein synthesis (d) Fat synthesis

9. Double membrane is absent in –

(a) Mitochondrion (b) Chloroplast (c) Nucleus (d) Lysosome

10. Name the tissue that makes the husk of coconut;

(a) Sclerenchyma (b)Parenchyma (c)Collenchyma (d)aerenchyma