Monday 27 March 2023

10th Hot Model Qn ppr 4

    10th Science Hot Model Paper - 4      

                        PART - A PHYSICS                  

I. Multiple Choice Questions:  5 X1= 5

1. Heating elements used in electric stoves are made from nichrome alloy because nichrome has

A] stability towards chemicals

B] low melting point

C] high resistance

D] very low resistivity

2. Concave mirrors are used in the device to observe the upper part of the teeth by a dentist because,

A] concave mirror produces magnified image

B] concave mirror forms diminished image

C] the image is inverted

D] the image is laterally inverted

3. Which one of the following is an effect of refraction of light?

A] Early sunrise

B] Tyndalleffect

C] Reddish colour of the sky during evening

D] Blue colour of the sky during day light

4. The factor on which the resistance of a conductor does not depends is

A] Area of cross section of the conductor

B] Length of the conductor

C] Material that is used to insulate the conductor

D] Nature of the material of the conductor

5. Planets do not appear to twinkle because the light coming from the planets

A] does not suffer multiple refractions

B] get scattered by atmospheric particles

C] undergoes dispersion

D] undergoes reflection

II. Answer the following questions:    3X1=3

6. If a charge of 10 Coulombs passes through a conductor in 5 seconds, what is the current that is flowing in the conductor?

7. When a suspended coil of a conductor connected to a source of current is brought near a magnetic field, the coil moves. Why?

8. Write 'u' 'v' 'f formula for a lens.

III. Answer the following questions: 2 X2= 4

9. Express Ohm's law mathematically. Calculate the resistance of a conductor through which 2 ampere current flows when the voltage applied across it is 200 volts.

10. Draw the ray diagram of formation of image by a convex lens, when the object is placed between '2F1' and 'F1'of the lens

IV. Answer the following questions: 4X3= 12

11. What is the advantage of A.C. in transmitting electricity from one place to another? What change do you make to convert A.C. generator into D.C. generator? A.C. is not suitable for  electrolysis  Why? 

OR

What is electromagnetic induction? What were the conclusions drawn by Faraday after conducting the experiment on electromagnetic induction? Induced emf in a generator depends upon what factors?

12. How can electrical energy be produced by i] wind ii] tidal waves?

OR

Explain briefly the following:

i] ocean thermal energy

ii] geothermal enname

13. What is a spectrum? Name the colours of the spectrum of white light in the order from high frequency to low frequency. In the following figure showing refraction of white light through a prism, name

i] angle of refraction

ii] angle of emergence

iii] angle of deviation

14. The prescription of an optician is +2D for both the eyes of a person. What is the eye disorder of the person? What type of lens is prescribed? What is its focal length?

OR

An object is placed at a distance of 60 cm from the optical centre of a convex lens. The focal length of the convex lens is 30 cm. At what distance is the image formed? What is the nature and magnification of the image?

V. Answer the following question: 1X4= 4

15. You are given an iron wire of length 10 cm. How do you find its resistance using a 12volt battery, voltmeter, ammeter and a plug key? Without breaking the wire, how do you decrease its resistance?

                     PART - B CHEMISTRY            

VI. Multiple Choice Questions: 1X1= 1

16. Which of the following is a reducing agent?

A] potassium permanganate

B] potassium dichromate

C] potassium metal

D] potassium chloride

VIl. Answer the following questions : 3X13

17. How can the rancidity of food be minimized?

18. Write the equation of the chemical reaction that takes place when silver chloride is exposed to light.

19. What is the chemical composition of rusted iron?

VIII. Answer the following questions:    3X2=6

20. Two oxides, one metallic and the other non-metallic, are both soluble in water. How do you experimentally decide which is the metallic oxide and which is the non-metallic oxide?

21. Draw the diagram of the apparatus used in demonstrating that acids conduct electricity

22. Draw the diagram of the apparatus used to demonstrate the action of steam on red hot iron.

OR

Draw the diagram of the apparatus used in the electrolytic refining of copper. Label cathode and anode.

IX. Answer the following questions:  3X2= 6

23. How do you experimentally distinguish between sodium carbonate and sodium hydrogen carbonate?

OR

a] What is pH value of a solution?

b] What is the colour of blue litmus paper and red litmus paper in the following freshly prepared solutions using distilled water? Give reasons

i] Potassium chloride solution.

i] Sodium hydrogen carbonate solution.

24. Write balanced chemical equations for the following reactions:

i] Hydrochloric acid is added to silver nitrate solution

ii] Zine metal is immersed in copper chloride solution

ii] Silver bromide is exposed to sunlight

X. Answer the following question:   1X4=4

25. a] State the modern periodic law.

b] How do the atomic radius/ atomic size and metallic nature of elements change across period and down a group in the modern periodic table?

c] What is the special feature of the 18th group in the modern periodic table?

XI. Answer the following question: 1X5=5

26. a] What are addition and substitution reactions?

b] How do you use an addition reaction to prevent the rancidity of vegetable oils?

c] What type of reaction takes place when a mixture of methane gas and chlorine gas are exposed to sunlight?

d] Write the equation for this reaction

                   PART - C BIOLOGY                 

XII. Multiple Choice Questions: 2x1=2

27 One of these does not belong to the group 

A] Ovary       B] Ovule 

C] Anther     D] Style

28. Which one of these receives stimuli?

A] Nerve ending     B] Cell body

C] Dendrite              D] Axon

XIII. Answer the following question: 2X1=2

29. Define transpiration.

30.  Why is the ozone layer important to us?

XIV. Answer the following question: 3X2=6

31. Draw the vertical section of a dicot seed and label (a) Plumule and (b) Radicle

32. Draw a diagram showing the germination of pollen on stigma

33. Forests are biodiversity hotspots'. Explain.

XV. Answer the following questions: 3x3=9

34. Draw the diagram of human excretory system and label:

i] Ureter      ii] Urinary bladder

35. Construct a food web

36. Differentiate between self-pollination and cross-pollination.

XVI. Answer the following questions:    2X4=8

37. Draw the diagram of vertical section of the human brain and label the parts responsible for

a] speech

b] maintaining blood pressure

38. i] What is bio-magnification?

ii] Construct an aquatic food chain.



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