Kendriya Vidylaya New Cantt Allahabad

KENDRIYA VIDYLAYA NEW CANTT ALLAHABAD

Periodical Test -1

Sub- Science MM-40

TIME-90 MIN CLASS-VIII

INTRUCTIONS:

1. All questions are compulsory.

2. Marks allotted against each question.

MCQ (1*3= 3)

1. Seed drill is used for

a- harvesting b- cleaning

c- Sowingd- weeding

2. Yeast is used in the production of

a- sugarb- alcohol

c- Hydrochloric acidd- oxygen

3. The process of conversion of sugar into alcohol is called

a- Nitrogen fixationb- moulding

c- Fermentationd- infection

4. Define animal husbandry. 1

5. What is combine? 1

6. Draw a diagram of virus. 2

7. Define biodegradable substances. Write two examples. 2

8. Explain the difference between thermoplastic and thermosetting plastic. 2

9. DEFINE : 2

(a)combustion (b) ignition temperature.

10. What is coke? Write its two uses.2

11. What are antibiotics? What precautions must be taken while taking antibiotics? 3

12. Write a short paragraph on the harms caused by microorganisms. 3

13. Why Sodium and potassium are stored in kerosene? 3

14. What are the advantages of using CNG and LPG as fuels? 3

15. Describe how coal is formed from dead vegetation. What is this process called? 3

16. Write down the five differences between fertilisers and manures. 5

17. What happens when 5

(a) Dilute sulphuric acid is poured on a copper plate

(b) Iron nails are placed in copper sulphate solution

Write word equations of the reactions involved.

…….x…….x…..x……x……x……

MARKING SCHEME

VLASS-VIII

SUB= SCIENCE

1.SOWING

2. ALCOHOL

3.FERMENTATION

4. Rearing of useful animals on commercial scale.

5.Machine having combined harvester & thresher.

6.diagram of virus fig.2.5 ,page no.19 of NCERT BOOK.

7.Decomposing of materials through natural processes.eg.vegetables peels, paper or any other

8.Thermoplastics: Deformed easily by heating,can be bent easily.

Thermosetting plastics: can not be soften easily by heating,can not bent.

9. Combustion: Chemical process in which a substance reacts with oxygen to give off heat

Ignition temperature: Lowest temperature…..a substance catches fire.

10.Atough,porous, black substance obtained from coal.manufacturing of steel,extraction many metals.

11.Antibiotics: medicines to kill or stop growrh of microorganisms.

Make the drugs less effective , may kill useful bacteria

12.Micro. …harmful…..cause diseases…..inhumans,plants,animals……..pathogens….spoil food….clothing & leather……

13.Reacts vigorously with oxygen&water

14.They are less polluting,cleanerfuelcan be used direcly at homes

15.About 300 millions …. Dense forest…..wetland……were compressed …..temperature ….high pressure……converted ….coal.

Carbonisation.

16.five differences in each.

17.(a)Copper sulphate,hydrogen gas.

Copper +sulphuric acid=copper sulphate +hydrogen gas

(b)deposit brown coat

Iron+ copper sulphate= iron sulphate +copper

X …… x….. xxxxx……..