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Question paper 1
1. In the given diagram which defect of the human eye is being corrected using a concave lens?
Answer:
In this diagram myopia or short sideness is corrected using concave lens.
2. Name the device shown in the given diagram. What is being prepared in it ?
Answer:
Biogas plant setup is shown in the given figure.
Biogas is being prepared in it.3. Zn(s)+CuSO4(aq) --> ZnSO4(aq) + CU(s)What type of chemical reaction is shown in above equation?
(a) Combination reaction
(b) Dissociation reaction
(c) Displacement reaction
(d) Double displacement reaction
Answer:
It is a type of displacement reaction.
4. Why do we apply paints on iron goods ?
Answer:
Iron is a metal which gets corroded when comes in contact with air so to prevent rusting they are painted with enamels paints.
5. In the diagram what is the sex of (A) and (B)
Answer:
Sex of A: Female which has XX chromosome.
Sex of B: Male which has XY chromosome.
PART B
6. Write two uses of Washing Soda.
Answer:
Two uses of washing soda:
(i) It is used for removing permanent hardness of water
(ii) It is used in the manufacture of glass, soap and paper7. Label 1 and 2 in figure.
Answer:
Level 1 is: A battery (usually of 6V)
Level 2 is: Nail8. (i) Write molecular formula of propane.
(ii) Write IUPAC name of
Answer:
(i) Molecular formula of propane:
C3H8
(ii) Bromo ethane or Ethyl Bromid9. Write Newland's Law of Octaves for classification of elements.
Answer:
Newland’s law of octaves:
In 1866 John Newland arranged the then known element in order of incasing atomic masses. He started with element having the lowest atomic mass (hydrogen) and ended with the element thorium which was 56th elements.
He found that every element eighth element had proper similar to that first.H e compared this to the octaves found in music, therefore, he called it ‘law of octaves’ it is a also known as Newland’s law of octaves10. Sodium [Na] and Sulphur [S] both are present in third period of modern periodic table. Which is more metallic and why ?
Answer:
Sodium is more metallic as it has the tendency to give away electron. But sulphur is a non-metal thus can only accept elecrons.
11. What is Autotrophic nutrition ? Give one example.
Answer:
Autotrophic nutrition: it is that mod of nutrition in which an organism makes its own food from simple inorganic materials like Co2 and H2O present in surrounding with the help of surrounding.
Eg: Green plants12. Why it is advised to take iodised salt ?
Answer:
Iodine is needed in the production of thyroxine hormone which helps in regulation of metabolism of fats proteins and carbohydrates to provide the best balance for body Deficiency of thyroxin leads to sculling of neck which is a symptom of goitre. So it is advised to iodized salt.
13. In the given diagram/figure label 1 and 2
Answer:
Label 1: Pituitary gland
Label 2: Testis14. Write two uses of spherical mirrors.
Answer:
Two uses of spherical mirrors are as follow:
(i) Concave mirrors are commonly used in torches, search lights and vehicle headlight. They are also used as shaving mirrors to see a larger image of the face.
(ii) Convex mirrors are used as rear view mirrors in vehicles.15. When does an electric short-circuit occur ?
Answer:
A short circuit primarily occurs when two current carrying bare come in contact with each other. This results in the current flowing through the result in a tripped breaker or blower fuse short circuit can occur in both DC and AC circuits.
PART C
16. Write chemical equation for the reaction taking place in the flask. Write name and one property of the gas evolved.
Answer:
Chemical equation:
Zinc + Sulphuric Acid → Zinc Sulphate +hydrogen
Zn + H2So4 → Zn So4 + H2
Gas evolved is Hydrogen.
Properties of Hydrogen gas
(i) High flammable
(ii) H2 Reacts with every oxidizing agent.17. Name the structure shown in the figure. Also label 1 and 2
Answer:
Structure shown in figure = Micelles
Label 1: Hydrophilic head
Label 2: Centre of micelle18. What are the components of the transport system in human beings ? What are the functions of these components ?
Answer:
Transport system in human being consists of heart, blood and blood vessels.
Heart: It is a pumping organ to push pull blood around the body. It receives the deoxygenated blood from various Parts of the body. It sends this impure blood to lunges for oxygenate on. Again after receiving pure blood from lungs it sends this oxygenated blood throughout the body.
Blood vessels: There is a network of blood vessels which contains arteries, veins and capillaries. They help in the circulation of blood throughout the body.
Blood: It is a fluid connective tissue. It consists of plasma RWC, WBC and blood platelets. Plasma transports food. CO2 and nitrogenous waste in dissolved form. RBC transports respiratory gases and hormones WBC Protects the body from infections and platelets prevent the loss of blood at the time of injury by forming blood clots.
19. How does the creation of variations in the species promote survival?
Answer:
All the variations in the species do not have equal chances of survival in environment. The survival of the variation depends upon the nature of variation different individuals have different chance. Selection of variations by environment factors from the basis for evolutionary processes. Thus variations may lead to increase survival advantages of the individuals due to positive adoption of tracts or may merely contribute to the genetic drift.
20. Which mirror is shown in the figure ? Where is object placed with respect to the mirror ? Write one characteristic of the image formed.
Answer:
Mirror shown in figure is concave mirror. Object is placed between pole and focus of mirror. Image formed is encaged and magnified. Mature of image is virtual and erect.
21. Why does rising Sun appears red in colour ?
Answer:
While sunset and sunrise the color of the sun and its sounding appear red. During sunrise, the sun is near to horizon and troupe the sunlight has to travel longer distance in the atmosphere due to this most of blue light(shorter wavelength ) are swatted away by the particles. The light of the longer wavelength (red color) will reach our eye. This way sun appears at sunrise red in colours.
22. Name the law shown in the figure. Label 1 and 2 according to this law
Answer:
Law shown in figure:
Fleming right hand rule.
Label1: magnetic field
Label2: current induced in conductor23. Write three characteristics of a good fuel.
Answer:
Characteristics of a good fuel:
(i) It should have a high calorific value
(ii)It should have a normal rate of combustion.
(iii)It should be easy to transport, handle and store
(iv)It should have least volatile material.
(v) It should have a low value of ash content after burning.
(vi) It should be economical and renewable.24. What is ozone and how does it affect ecosysten ?
Answer:
It is a molecule formed by three atoms of oxygen. At the higher levels at the atmosphere, it shields the surface of the earth from UV radiations from the sun.
It may affect any ecosystem in the following ways.
(i) At the surface of the earth, it is a deadly poison for all lower forms of life.
(ii) If this layer depleted, then it may cause cancer in human being including other plants and animals.
25. Why should we conserve forests and wild life ?
Answer:
Wildlife and forests should be conserved for the following reasons:
(i) Conservation of wildlife and forests in vital for the ecological stability of a particular area.
(ii) Forests provide employment to a large number of people and also help in generating revenue.
(iii)Forests are necessary for the formation of humus and for maintaining soil fertility.
(iv) Forests are the habitat for wildlife and they are an important constituent of the various food chain and food webs.
(v) many fruits, medicines, dyes, sandalwood and bamboo is obtained from forest by the local people.
PART D
26. With the help of a labelled circuit diagram derive a formula to find combined resistance (R) when two or more resistances (R1,R2, R3 ..,:,..) are connected in parallel taking symbol potential difference (V) and current (I).
Answer:
Let us consider arrangement of three resistors joined in parallel with a combination of cell as shown in figure.
It is observed that the total current I, is equal to the sum of separate current through each branch of combination.
I = I1 + I2 + I3 ….(i)
Let Rp be the equivalent resistance of the 11 combinations of resistors. By applying Ohm’s law to parallel combination of resistors we have.
I + V/Rp ..…(ii)
On applying Ohm’s law to each resistor, we have.
I1 = V/R1, I2 = V/R2 I3 = V/R3 ……….(iii)
From (i) and (ii) we have
or
Thus we may conclude that reciprocal of the equivalent resistance of a group of resistance joined in 11 equal to the sum of reciprocals of the individual resistance.
OR
26. (a) Name and define unit for electric current.
(b) On what factors does the resistance of a conductor depends?
Answer:
(a) Unit for electric current: Ampere
Ampere:
When/coulomb charge flow through a wire in/ second then current is one ampere
(b) Resistance of a conductor depends upon flowing factors:
(i) Length of conductor
(ii) Cross section area
(iii)Nature of conducting material27. (a) Draw electron dot structures of Sodium(Na), Oxygen(O) and Magnesium(Mg).
(b) Why do ionic compounds have high melting points?
Answer:
(a) Sodium:
(Na)
Oxygen:
(O)
Magnesium:
(Mg)(b) In ionic compounds, the constituent particles are the ions. As a result, these are held together by the strong ionic bonds on the principal forces are the electrostatic force that holds the ions together in a crystal lattice. Breaking the crystal lattice means pulling negative and the positive ions apart which requires a lot of energy as the electrostatic fours are very strong. Hence the melting and boiling point of ionic compounds are very high.
OR
27. With the help of labelled diagram prove by an experiment that both oxygen/air and water are necessary for rusting of iron.
Answer:
Experiment
Take three test tube and place a dirt free iron nail in each of these tubes in the first tube anhydrous calcium chloride is added and the test tube is closed in the second test tube distilled water and layer of oil is added and the test tube is closed in the third test tube top water is added. The nail is dipped in such a way that a part of it is exposed to the damp air present inside the tube.
Observation:
(i)the nail in the first and the second test tube do not rust.
(ii)the nail present in the third test tube rusts.
Conclusion:
We can conclude that both air and water are necessary for rusting of iron.28. With the help of a labelled diagram explain human male reproductive system/organs.
Answer:
Male reproductive system:
Male reproductive organs include the testis, seminal vesicles, penis and some associated glands such as prostate gland.Testis:
It is the most important Male reproductive organ it produces sperms. Sperm from the testis pass through sperm duct known as sperm vas deferens.Prostate gland:
the sperm duct from both side near the base of urinary bladder, opening into a single tube called urethra. This junction occurs inside the outside of the body through an organ called. It carries both urine and seminal fluid.Penis:
Muscular, tubular organ made up of loose tissue with space in between. This is called erectile tissue. On Bering stimulated the erectile tissue fill with blood, making the penis erect and firm so that it may enter the vagina of female and discharge the sperm.Sperm:
It is a male gamete. It has a head a long tail, which helps it swim towards the ovum (egg).OR
28. What are the different methods of contraception?
Answer:
Contrastive methods can be broadly divided into following types Natural method:
It involves avoiding the chance of a meeting of sperms and ovum in this method, the sexual act is avoided from day 10th to 17th of menstrual cycle because during this period, ovulation is expected and therefore the chances of fertilization are very high.Barriers method:
In this method, the fertilization of ovum and sperm is prevented with the help of barriers. Barriers are available for both males and females. Condoms are barriers made of their rubber that are used to cover penis in males and vagina in females.Oral contrastive:
In this method, tablets or drugs are taken orally. These contain small doses of hormones that prevent the release of eggs and thus fertilization cannot occur.Implants and surgical methods:
Devices such as the cooper copper placed in uterus to prevent the gamete transfer. It includes the blocking of vas deferens to prevent the transfer of sperms known as vasectomy similarly fell opium tube of female can be blocked so that the egg will not reach the known as tubectomy.
Question paper 2
1. Zns+CuSO4aq --> ZnSO4aq + CUs What type of chemical reaction is shown in above equation?
(a) Combination reaction
(b) Dissociation reaction
(c) DisPlacement reaction
(d) Double disPlacement reaction
Answer:
2. In the diagram what is the sex of (A) and (B)
Answer:
3. Name the device shown in the given diagram. what is beingprepared in it ?
Answer:
4. In the given diagram which defect of the human eye is being corrected using a concave lens
Answer:
5. Why do we apply paints on iron goods ?
Answer:
6. write Newland's Law of 'octaves' forclassification of elements.
Answer:
7, What is Autotrophic nutrition ? Give one example.
Answer:
8. In the given diagram/figure label 1 and 2
Answer:
9. When does an electric short-circuit occur ?
Answer:
10. Write two uses of Washing Soda.
Answer:
11. Write molecular formula of Propane
Answer:
12. Sodium [Na] andSulphur [S] both are present in third period of modern periodic table.Which is more metallic and whY ?
Answer:
13. Why it is advised to take iodised salt ?
Answer:
14. Label 1 and 2 in the figure
Answer:
15. Write two uses of spherical mirrors.
Answer:
f.6. Which mirror is shown in the figure ? Where is object placed with respect to the mirror ? Write one characteristic ofthe image formed
Answer:
17. Name the law shown in the figure. Label 1 and 2 according to this law.
Answer:
18. What is ozone and how does it affect ecosystem ?
Answer:
19. Write chemical equation for the reaction taking place in the flask. Write name and one property of the gas evolved.
Answer:
20. What are the components of the transport system in human beings ? What are the functions of these components ?
Answer:
21. Why should we conserve forests and wild life ?
Answer:
22. Name the Structure shown in the figure.Also label 1 and 2
Answer:
23 How does the creation of variations in the species promote survival ?
Answer:
24. Why does rising Sun appears red in colour ?
Answer:
24. Write three characteristics of a good fuel.
Answer:
26. (a) Draw electron dot structures of Sodium (Na), Oxygen (O) and Magnesium (Mg)
(b)Why do ionic compounds have high meltingpoints ?
Answer:
27. With the help ofa labelled diagram explain human male reproductive system/organs.
or
What are the different methods of contraception ?
Answer:
zg. with the help of a labelled circuit diagram derive a formula to find combined resistance (R) when two or more resistances (R,, &, \ ......) are connected in parallel taking symbols potential difference (V) and current (I).
or
(a) Name and define unit for electric current.
(b) On what factors does the resistance ofa conductor depends J
Answer: