# Class 10 Science 2066 Pastpaper

## Central Development Region

Full Marks : 75
Pass Marks : 24
Time : 02:15:00
Q.NO. 1 (a)

What is the difference between fall of parachute on the earth and that on the moon? What is the effect of gravity on the falling object? If two masses 'X' kg and '200' kg are at a distance of 20 m and gravitational force of attraction between them is 3.335 x 10-9N. Calculate the value of 'X'.

[Marks : 1+1 +2 .5=4.5 ] Show Ans

Q.NO. 1 (b)

Why is possibility of energy crisis in the world? Mention any one measure to solve the energy crisis.

[Marks : 2+1=3 ] Show Ans

Q.NO. 2 (a)

Answer the following questions after observing the given diagram of hydraulic press. i) If the cross section area of cylinder 'A' and 'B' are 0.5m2 and 10m2 respectively, what magnitude of effort is to be applied on cylinder ‘A' to balance the load of 1,000N on cylinder ‘B’?
ii) On what principle does this machine work? State the principle also.

[Marks : 1.5+2=3.5 ] Show Ans

Q.NO. 2 (b)

Give reasons:
The bottom of the wall in a dam is made comparatively thicker, why?
An egg sinks in pure water but floats on concentrated solution of salt and water, why?

[Marks : 2+2=4 ] Show Ans

Q.NO. 3 (a)

What types of defect is found in the given diagram of the eye? Draw a diagram to show how this defect can be corrected, if focal length of lens of the spectacles needed for this eye is 50 cm, what will be the power spectacles? [Marks : 0.5+ 1 +2=3.5 ] Show Ans

Q.NO. 3 (b)

Give two differences between heat and temperature. A beaker is filled with water. Not single drop can be added. The temperature of water is 4°C. What will happen if it is cooled? Explain with reason.

[Marks : 2+2=4 ] Show Ans

Q.NO. 4 (a)

What is fuse? What type of connection of bulb is done in domestic circuit? Give two advantages of this connection.

[Marks : 1+0.5+2=3.5 ] Show Ans

Q.NO. 4 (b)

Define transformer. Why is the core of transformer laminated? 10 bulbs of 60 watt each and two heaters of 1500 watt each are used for two hours daily. Find the units of electricity consumed in 30 days.

[Marks : 1+ 1+2=4 ] Show Ans

Q.NO. 5 (a)

Give the answer of the following questions with the help of the given table :

 Na Mg Al Si P S CI Ar 2.8.1 2.8.2 2.8.3 2.8.4 2.8.5 2.8.6 2.8.7 2.8.8

i) Which period belongs the given elements belong?
ii) Which blocks do Mg and Ar belong to?
iii) Identify one active metal, active non-metal and inert gas.
iv) Write the chemical equation of the reaction between more active metal and more active non-metal. What type of chemical reaction is it?

[Marks : 0.5+2x0.5+3x0.5+ 1 + ] Show Ans

Q.NO. 5 (b)

Draw neat and labelled diagram for the preparation of carbon-dioxide gas in laboratory. Write the structure formula of glycerol. Which compound is formed if all 'OH' groups are replaced by ‘H’?

[Marks : 2+0.5+0.5=3 ] Show Ans

Q.NO. 6 (a)

What is aqua regia? Which metal is obtained from the ore argentite? Write the balanced chemical equation for the reaction when that metal is put into concentrated sulphuric acid.

[Marks : 1 +0.5+2=3.5 ] Show Ans

Q.NO. 6 (b)

What is chemical pollution? Write down the full form of D.D.T. Write a name of each chemical fertiliser containing nitrogen and phosphorus. Write down any two differences between acid and base.

[Marks : 1+1 +2x0.5+2x0.5=4 ] Show Ans

Q.NO. 7 (a)

Draw the diagram of bacteriophage virus and label its two parts. What is reflex action? Which parts of nervous system conduct this action?

[Marks : 2+ 1+0.5=3.5 ] Show Ans

Q.NO. 7 (b)

b. Give reasons:
i) The person suffering from anaemia feels tired after walking short period.
ii) Right auricle is larger than left auricle.

[Marks : 2+2=4 ] Show Ans

Q.NO. 8 (a)

How many chromosomes are there in ovum and zygote and why? Which type of cell division is indicated by the given diagram? Where does this type of cell division take place? Write its one importance. [Marks : 1+1+0.5+0.5+1 =4 ] Show Ans

Q.NO. 8 (b)

What is the gametophyte of fern called? Draw its diagram and label its male and female parts. Write importance’s of mushroom.

[Marks : 0.5+ 1+1+1 =3.5 ] Show Ans

Q.NO. 9 (a)

What is variation?  Draw a chart to show the types of offspring’s produced in F1, and F2 generations after the cross fertilisation between pea plant with red flower and that with white flower. Show genotype and phenotype in the chart. (Red flower is dominant.)

[Marks : 1 +3=4 ] Show Ans

Q.NO. 9 (b)

What is denitrification? Which type of living being is the mushroom? Why the number of producer is is larger than consumer in nature? Gymnosperm has no real fruit, why?

[Marks : 1+0.5+1+1 =3.5 ] Show Ans

Q.NO. 10 (a)

Mention any three reasons of launching artificial satellites into the space. What is black hole? Give the name of galaxy in which our solar system lies.

[Marks : 1x3+1 +0.5=4.5 ] Show Ans

Q.NO. 10 (b)

Write two effects of depletion of ozone layer. What is acid rain?

[Marks : 2+ 1 =3 ] Show Ans