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Previous year question paper with solutions for Science Mar-2018
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Question paper 1
1.Four options are given in each part of this question .Write the correct answer in your answer book.
(i) The chemical formula of common salt is-
(i) NaCl (ii) HCI (iii) NaOH (iv) HNO3
Answer:
(i) NaCl
(ii) The PH of a solution is 7. This solution will be-
(i)Acidic (ii) Alkaline (iii) Neutral (iv) None of these
Answer:
(iii) Neutral
(iii) Which of the following is a plant hormone –
(i)Insulin (ii) Thyroxin (iii) Oestrogen (iv) Cytokinin
Answer:
(iv) Cytokinin
(iv) The Unit of resistance is-
(i)Volt (ii) Ohm (iii) (iv) Joule
Answer:
(ii) Ohm
(v) The focal the conventional source of energy is-
(i)Fossil Fuels (ii) Solar Energy (iii) (iv) Nuclear Energy
Answer:
(i)Fossil Fuels
2. Give an example of displacement reaction.
Answer:
3.Given an example of animal hormone that secretes from Pituitary gland.
Answer:
Pituitary gland secrets the growth hormone.
4. Define electromagnetic induction.
Answer:
The process by which a changing magnetic field in a conductor induces a current in another induction is called electromagnetic induction.
5.Write Snell’s law of refaction.
Answer:
The ratio of sine of angle of incidence to the sine of angle of refraction is a constout for the light of a giver colour and fir the given pair of media this law is know as Snell’s law of refraction.
6.From Which radiation radiated by sun the Ozone layer pro the earth ?
Answer:
The Ozone layer protects the earth from UV radiation of the sun.
8. On the basis of nomenclature of carbon compounds name the following compounds-
(i) (ii)Answer:
(i) Chloropropane
(ii) Methanal9. Differentiate between pollination and fertilisation.
Answer:
Pollination fertilisation It is the process of deposition of pollen grains on stigma of flower.
External agents like wind insects etc are req to carry out pollination.
Site of pollination is stigma of flower.
This process take place on outer parts of flower.It is fusion of make gametes with female gametes of the flower.
No external agent is req to carry out fertilization
Site of fertilization is ovary of the flower.
This process take place inside the flower.10.What is saliva ? what is its role in the digestion of food?
Answer:
Saliva is the watery flied which is secreted by saliva glands when we rat something
The saliva any lase that breaks down starch in food to giver simple sugar
This makes food easy to get digested also saliva makes food moist & it because easy to ingest it.11.How is the sex of child determined in human beings ?
Answer:
The sex of humans is determined by the type of sex chromosomes present in the child It the sex chromosomes are XX it means the child is a feniale to if the chromosomes are XY it means the child is a male
12.Why is the tungsten almost used as a filament of electric lamp ? clarify.
Answer:
Tungsten is a good electric conductor with high melting point It does not melt due to high heat producer by electricity So it is used as a filament in electric lamp.
13.What are the factors on which the resistance of a conductor depends ? Explain.
Answer:
The factors on which resistance of a conductor depends are:-
(i) Length of (l)
(ii) Area of cross section of (A)
(iii) Nature of material used14. What do you mean by spectrum of light ? Which colours of spectrum deviates the most and which the least ?
Answer:
When of White light falls on a prism it splits into a le and of colours This le and of colours is known as spectrum
The violet colours of spectrum deviates the most while red colours of spectrum deviates the least.15.What is meant by renewable and non-renewable sources of energy ? Give one Example of each.
Answer:
renewable sources of energy :- The sources Which can always be replenished are called renewable sources They cannot Stop providing energy Eg Sun used etc.
non-renewable sources of energy :- The sources of energy Which once used cannot be replenished are called non-renewable sources of energy Eg. Fossil fuels as cool petroleum natural gas etc.16.What is modern period law? Clarify the meaning of groups and periods in modern periodic table.
Answer:
Modern period law the physical & chemical properties of element are the periodic function of the atomic numbers the various elements with similar properties after certain interval.
Group :- The element present in the same vertical column of periodic table represents a group they possess physical & chemical properties.
Periods :- The elements present in the rows of periodic table represents the periodic .17. (i) What are alloys? Give its two example also.
Answer:
An alloy is a homogenous mixture of two or more metals or a metal and a non-metal
For eh:- (i) Bsass an allay of copper & zine
(ii) Bronze an alloy of copper & tin(ii) Name two metals which are found in nature in the free state.
Answer:
Silver & Gold are the two metals that are found in free state in nature.
Or
A non-metal X exists in two different forms Y And Z is the hardest natural substance where Z is a Good conductor of electricity Identify X,Y And Z.Answer:
The non-metal X is carbon
The hardest natural substance y is
The good conductor of electricity Z is prsaphite18. What happens when (write only chemical equation)-
(i) Zine reacts with sodium hydroxide.Answer:
(ii) Carbon dioxide gas is passed in line water.
Answer:
(iii) Zips is heated upto 373 K.
Answer:
19.Draw longitudinal section of a flower and label following parts in it.
(i) Anther (ii) Stigma (iii) OvaryAnswer:
20. (i) What are the differences between aerobic and anaerobic respiration ?
Answer:
aerobican anaerobic respiration It Takes place in the presence of oxygen
Here complete oxcidation of glucose take place
End products are and water
Lots of energy is released
It occurs in plant & cellsIt taken place is the absence of oxygen.
Here the glucose is incompletely oxidised
End products are ethyl alcohol or lactic acid &
Less ancount of energy is released
It in anerobbacterica& human nuscle cells(ii) Why is the use of lodised Sali advisable ?
Answer:
In dised salt is adirsed to use lrcause it prevrnts goitre helps in proper functioning of thysoid glond
21. Draw a neat and clean diagram of human alimentary canal and label the following parts in it-
(i) Stomach (ii) Liver (iii) Large intestineAnswer:
Or
Draw a neat and clean diagram of human respiratory system and label the following parts in it-
(i)Lung (ii) Trachea (iii) DiaphragmAnswer:
22. (i) An electric bulb is rated at 200 V – 100 W What will be its resistance ?
Answer:
(ii) Write two properties of magnetic field lines.
Answer:
Characteristics of magnetic field lines.:-
(i)they are directional in nature, north pole and south pole out side the magnet and south pole to north pole inside the magnet
(ii)two magnetic field lines never cross each other23.A 4 cm long object is placed at a distance of 20 cm from a concave mirror of focal length 15 cm Find the position size and nature of the image.
Answer:
Or
What is mean by myopia ? Write the cause and correction of this defect.Answer:
Myopia is also known as nearsightedness a person with more badhiya can see nearby object clearly but cannot see distant object clearly
Causes :- (1)Excessive is cultivate of the eye lens
(2) Elongation of eye Ball
Correction:- this Defect can be corrected by using concave lens of the suitable power24. (i) Name any two abiotic components of environment .
Answer:
Two antibiotic compound from environment are water and soil
(ii) What do you mean by nuclear fusion ? Explain with example .
Answer:
Nuclear Fission means joining lighter nuclear to make a heavy nucleus
For example when hydrogen or hydrogen isotopes combine they create Helium as
2H + 2H 3He + (n)
Hydrogen helium (neutron)
It releases tremendous amount of energy such as nuclear fusion reaction are sources of energy in the sun and other stars25.(i) What is homologous series ? Explain With an example.
Answer:
A series of compound in which the same functional group substitute for hydrogen in a carbon chain is called him or genius series the compound is in it passes similar chemical properties for example CH3,OH,C2H5OH, C3H7, OHcl, C9H9OH All are having similar chemical properties so they belong to homologosis series.
(ii) What is Esterification ? Explain with chemical equation ?
Answer:
Esterification reaction :- It is the reaction between an acid and alcohol in the presence of catalyst it can be assured by following reaction.
26. (i) Name a meted and a non- metal found in liquid state at normal temperature.
Answer:
Metal and nonmetal are found in liquid state at room temperature are Mercury and bromine resp.
(ii) Mention the general properties of ionic compounds and clarify that why do ionic compounds have high melting points ?
Answer:
General properties of ionic compound are
1. they are solid and hard
2. They have high MP and BP
3. They are soluble in water
4. They are good conductor of electricity
Ionic compound having Hai MP because of strong force of attraction present between the ions of ionic compoundOr
(i)What is the difference between roasting and calcination ? What the chemical reaction that takes place during roasting and ealeination of zine ores.Answer:
Roasting Calcination They are heated in excess of air
This is used for Sulphide ore
SO2 is produced along with metal oxidethe ore is heated in absence of are limited supply of air
This is used for carbonate votes
CO2 is produced along with metal oxide(ii) Identify the substance that is oxidised and reduced in the following reaction-
Answer:
27. (i) Where does the digestion of fat takes place in our body ?
Answer:
Fat is digested in small intestine of our body.
(ii) What will happen to a plant if is xylem is removed ?
Answer:
Removal of xylem will lead to wilting of leaves of a plant and then death of the plants.
(iii) Explain analogous and homologous organs with one example each.
Answer:
Analogous organ:- organ which different in the organ but perform same function are called and a leg on leg for example Wings of insect and Bird
Homologasis organ :- organ which have same organ or basic structure but differ in their functioning are card homologasis organ example Wings of bat and arms of human28.In the given circuit diagram calculate-
(i) The current flowing through each resistor(ii) The total resistance of the circuit
(iii) The total current in the circuit.Answer:
29.(i) State Heming left hand rule
Answer:
According to Fleming's left hand rule the fore finger Thumb and middle finger of left hand are traded such that they are mutually perpendicular if first finger. The direction of magnetic field in the second finger in the direction of current then thumb will. The direction of motion or force acting conducto
(ii) Give two differences between alternating current and direct current.
Answer:
Alternating current
Direct current
Electricity charge change its direction periodically
Electricity charge flow only in one direction
AC current can travel safely add long dice
DC current can be travel to along dies because of high energy loss
The generating freq.
The frequencyAlternating current Direct current Electricity charge change its direction periodically
AC current can travel safely add long dice
The generating freq.
Electricity charge flow only in one direction
DC current can be travel to along dies because of high energy loss
The frequency
Or
(i)why does the sky appear dark instead of blue to an astronaut ?Answer:
In space there is no atmosphere to scattered the light as no light gets scattered the sky appears to be dark instead of blue to the the astronauts
(ii) Light enters from air to glass having refractive index 1.50 what will be the speed of light in glass if the speed of light in air is
Answer:
30.(i)What is the importance of forest as a resource ? Clarify.
Answer:
The forests are important natural and ecological resources they provide us following benefits.
(i) regular Global temperature and climate.
Ii production house of oxygen and scavangers of Co2
Iii provide Habitat to word life
IV they provide us Timber flute food bamboo raw material for Food Industry and other miscellaneous product(ii) What do you mean by water harvesting ? Write two traditional systems of water conservation
Answer:
Water harvesting means conversation of water from different sources like rain seasonal rivers into pond or Lake this provide water for usage for long period of time
traditionally following ways were used
underground tank they were made underground and water was stored in them and were covered from top
ponds ponds were used to collect large amount of water in openOr
(i)What do you mean by the three ‘R’ to save the environment? Write in briefAnswer:
The 3 R 's to save environment are reduce reuse and recycle
Reduce:- the plastic waste wastage or non degradable waste should be reduced to use the reduction of in usage will save environment from pollution
Reuse:- the material that can be reused should not be thrown away they should be used in different possible ways
Recycle:- the plastic waste that cannot be reuse should be recycle and could be used in different forms this will reuse the plastic waste(ii)For which specific work the Amrita Devi Bishnoi national award is given ?
Answer:
Amrita Devi Bishnoi award is given for significant contribution in field of Wildlife Protection.
7.Write only chemical equation for the reaction of preparation of bleaching powder Give its one use also.
Answer:
The chemical equation for the preparation of bleaching powder is,
The bleaching powder is used for bleaching cotton and linen in textile industry for bleaching word pulp in paper factories for bleaching washed clothes in laundry.