SAMPLE PAPER

SCIENCE

SET - III

Name any two non-renewable sources of Energy.

Write any two examples of harmful radiations emitted by the nuclear wastes.

Give one example each of a primary and a secondary fuel.

State  any two advantages of food preservation.

Name the group of chemical compounds which adversely affect the ozone layer.

Write the name and chemical formula of any one compound having water of cystallization indicating the number of molecules of water in it.

Q.8.

In which season of the year the constellation scorpio and Orion are visible in the northern hemisphere?

Name any two characteristics that define the orbit of an artificial satellite.

What are the solids, liquids and gaseous products formed when wood is heated in the absence of air?  What is name of this process ?

Describe the cycle of carbon occurs in nature.

The mass number of elements A,B,C and D are 2,35,135 and 233 respectively. which one of these will be most suitable for (a) nuclear fission (b) and nuclear fusion.  Write any one difference between the two processes.

Explain how abiotic factors may affect food grains during their storage.

A farmer was advised not to use a particular type of fertilizer for his crop after harvesting a crop of peas.  give one reason for such as advice.  Name any two crops other than pea crop which might have shown the same effect.

What happen when ethylalcohol and acetic acid react with each other in the presence of concentrated sulphuric acid.

The calorific value of three fuels A,B and C are 33 KJ, 48 KJ and 150 KJ respectively.  A is solid, B is liquid and C is gas at room temperature.  On combustion both 'A' , 'B' produce CO₂ while C explodes forming steam.  B and C leave no residue after combustion while A leaves some solid residue.  Which one of those three fuels is most ideal?  Give two reasons to support your answer.

It was found that the waste discharged by a newly constructed factory around a lake had a number of chemicals in it.   Some of these formed a thick oily layer on the water surface while a few other reacted with oxygen dissolved in water.  Explain how would these changes affect aquatic life in the lake.

The distance between a pair of galaxies 'A' and 'B' is 'x' light years and that between another pair 'C' and 'D' is 2x light years.  In which pair the two galaxies be receding from each other with greater speed.  State the law and the scientist who proposed it.

Name the essential nutrients of food.  State major functions of any two of them.  What is the role of roughage in our diet ?

Write three uses of aluminium.   State the properties on which these uses are bases.

Describe the main stages in the life of a star of the size of sun.

A student constructed a model of a box type solar cooker.  He used a transparent plastic sheet to cover the open phase of the box.  He found that the cooker does not function well.  What modification should be made to enhance the efficiency? Give reason.

Why do many people become obese as their age advances? Explain.  Name any two diseases to which these people are most susceptible.

Describe with the help of a flow diagram the transfer of energy from sun to top carnivores.

Explain how TV programmes are transmitted to remote area through the INSAT satellites.

On complete combustion one gram of coal liberated 21 KJ of energy.  This energy is utilized to heat 500 g.  of water.  Calculate the rise in temperature of water.  (Specific heat of water = 4200 J/Kg⁰C)

The efficiency of a diesel engine is 40 %.  If 10,000 of energy is liberated by the combustion of diesel in the engine, then how many kg. of water can be fitted by it through a height of 10 m. (g.=10 m/s²)

A gas having one carbon atom in its molecule is collected by downward displacement of water.  It burns with blue flame and the resulting gas turns lime water milky.  Name e the gas and state its two properties based on the above observations. Write the chemical equation of the reaction that takes place when the gas burns in air.

Discuss in brief the various strokes in the working of a diesel engine with the help of neat diagram.  In which stroke do we get energy from the engine ?

Explain how the high yielding varieties of wheat were obtained to increase its production in our country.  How do these varieties differ from traditional varieties in respect of input and yield ?

An element belonging to the VI group of the periodic table is named by a special technique based on the fact that it has comparatively low melting point.  Identify the element and explain the process of its extraction.  What happens when this element reacts with (a) hot concentrated sulphuric acid and (b) concentrated nitric acid write chemical equations to represent the above reactions.

Metal M occurs in earth's crust as its oxide M₂O₃.  The alloy of this metal is used in making aircrafts.  Identify the metal M and explain the steps involved to obtain this metal from its ore in the form of oxide.