Students must start practicing the questions from RBSE 10th Science Model Papers Set 6 with Answers in English Medium provided here.
RBSE Class 10 Science Model Paper Set 6 with Answers in English
Time: 2:45 Hours
Maximum Marks: 80
General Instructions to the Examinees:
- Candidate must write first his/her roll no. on the question paper compulsorily.
- All the questions are compulsory.
- Write the answer to each question in the given answer book only.
- For questions having more than one part, the answer to those parts are to be written together in continuity.
Part – A
1. Multiple Choice Questions :
Choose the correct alternative for the following questions and write them in the answer book.
(i) The kidneys in human being are a part of the system for: [1]
(a) nutrition
(b) respiration
(c) excretion
(d) transportation
Answer:
(c) excretion
(ii) The inner lining of stomach is protected by one of the following from hydrochloric acid: [1]
(a) pepsin
(b) mucus
(c) salivary amylase
(d) bile
Answer:
(b) mucus
(iii) Spinal cord originates from : [1]
(a) cerebrum
(b) medulla
(c) pons
(d) cerebellum
Answer:
(b) medulla
(iv) The main function of abscisic acid in plants is to : [1]
(a) increase the length of the cells
(b) promote cell division
(c) inhibit growth
(d) promote growth of stem.
Answer:
(c) inhibit growth
(v) Magnification produced by a rear view mirror fitted in vehicles :[1]
(a) is less than one
(b) is more than one
(c) is equal to one
(d) can be more than one or less than one depending upon the position of the object infront of it.
Answer:
(a) is less than one
(vi) A spherical miror and a thin spherical lens have each a focal length of -15 cm. The mirror and lens are likely to be: 1
(a) both are concave
(b) both are convex
(c) the mirror is concave, but the lens is convex
(d) the mirror is convex, but the lens is concave
Answer:
(a) both are concave
(vii) What is the minimum resistance which can be made using five resistors each of 1/5 Ω, [1]
(a) 1/5 Ω
(b) 1/25 Ω
(c) 1/10 Ω
(d) 25 Ω
Answer:
(b) 1/25 Ω
(viii) When a conducting wire is streched to double of its initial length, then which property of conducting wire increases? [1]
(a) resistivity
(b) resistance
(c) volume
(d) density
Answer:
(d) density
(ix) The device used for producing electric current is called a: [1]
(a) generator
(b) galvanometer
(c) ammeter
(d) motor
Answer:
(a) generator
(x) In which of the following the identity of initial substance remains unchanged? [1]
(a) curdling of milk
(b) formation of crystals by process of crystallisation
(c) fermentation of grapes
(d) digestion of food
Answer:
(d) digestion of food
(xi) Galvanisation is a method of protecting iron from rusting by coating with a thin layer of: [1]
(a) gallium
(b) aluminium
(c) zinc
(d) silver
Answer:
(a) gallium
(xii) Dilute NaOH solution and solid sodium carbonate: [1]
(a) react only on heating
(b) react very slowly
(c) do not react
(d) react vigorously
Answer:
(d) react vigorously
2. Fill in the blanks :
(i) ………………………………. is a tuft of blood capillaries inside the cup of a Bowman’s capsule kidney. [1]
Answer:
Glorerulus,
(ii) Iodine is necessary for the synthesis of ………………………… hormone. [1]
Answer:
Thyroxine,
(iii) …………………………….. layer prevents UV rays from the sun to penetrate down the earth. [1]
Answer:
Ozone,
(iv) ………………………………….. means “hug the tree”. [1]
Answer:
Chipko,
(v) The medium in which light travels fast is called ……………………………… . [1]
Answer:
rarer medium,
(vi) SI unit of electric current is ………………………….. . [1]
Answer:
Ampere.
3. Very Short Answer Type Questions (Answer the questions in one word or one line)
(i) What is the largest artery of our body called? [1]
Answer:
Aorta,
(ii) Which part of the brain maintains posture and balance of the body? [1]
Answer:
Cerebellum,
(iii) What enables the decomposers to digest the substance present in their environment? [1]
Answer:
Enzymes which are released in their surroundings,
(iv) Name the three ‘R’ of the conservation strategy. [1]
Answer:
Reduce, Reuse and Recycle,
(v) Which type of mirrors are used to give an erect and enlarged image of an object? [1]
Answer:
Concave mirror,
(vi) Define 1 ohm. [1]
Answer:
1 ohm is the resistance of conductor when the potential difference across its ends is 1 V and 1 A current is flowing through it,
(vii) Name the SI unit of magnetic field. [1]
Answer:
Tesla (T),
(viii) Name the rule which is used to find the direction of magnetic field due to current-carrying circular loop? [1]
Answer:
Right-hand Rule,
(ix) Name the salt used in freezing mixtures? [1]
Answer:
Sodium chloride,
(x) What happens to the H+ ions and temperature of the solution, when an acid is neutralised? [1]
Answer:
(a) H+ ions of acid combine with OH– ions of alkali to form water (H2O) and temperature of the solution rises,
(xi) What contributes to the basic character of a base? [1]
Answer:
Hydroxyl ions,
(xii) What would be the pH of a salt of weak acid and strong base? [1]
Answer:
More than 7.
Part – B
Short Answer Type Questions – Write the answer of questions 4 to 16 (Word limit 50 words)
Question 4.
Why is it necessary to separate oxygenated and deoxygenated blood in mammals and birds? [2]
Answer:
The mammals and birds are warm-blooded animals. To maintain their body temperature their energy requirements are very high. In other words, they have high metabolic rate. To fulfil this they need a highly efficient supply of oxygen to the body cells. This can be done by keeping the oxygenated and deoxygenated blood separated in mammals and birds.
Question 5.
What are sex chromosomes? How many sex chromosomes are there in human beings? [2]
Answer:
Chromosomes which are related to determine sex are known as sex chromosomes. In human being there are 46 chromosomes in a diploid cell. Out of these 22 pairs are autosomes and one pair is sex chromosome. Sex chromosomes are XY in human male, in human female sex chromosomes are XX.
Question 6.
Why are the traits acquired during the lifetime of an individual not inherited? [2]
Answer:
A change in the DNA of reproductive tissue (gonads) of an individual is transmitted to the offspring. Traits acquired by an individual during the lifetime are simply change of body cells, like building up of muscles or learning a skill etc. They do not involve reproductive cells hence, not inherited.
Question 7.
Give any two ways in which non-biodegradable substances would affect the environment. [2]
Answer:
- Some non-biodegradable substances, like pesticides, enter the food chains. Their biological magnification affects human being and other animals of ecosystem.
- Disposal of non-biodegradable substances, like plastic, polythene etc., has become a serious problem. They choke the drains, create many problems in environment.
Question 8.
Name the type of mirror used in following situations : [2]
(a) Headlights of a car
(b) Side/rearview mirror of a vehicle.
Answer:
(a) Concave mirror. When light source is placed at the focus of the mirror, then on reflection a strong parallel beam of light emerges.
(b) Convex mirror. Field of view of convex mirror is larger and it forms virtual, erect and diminished images of objects
behind.
Question 9.
A wire of given material having length l and area of cross-section A has a resistance of 4 Ω.
What would be the resistance of another wire of the same material having length l/2 and area of cross-section 2A?[2]
Answer:
For first wire let resistance be R1
∴ R1 = \(\rho \cdot \frac{l}{\mathrm{~A}}\) = 4 Ω (given)
For second wire let resistance be R2,
R2 = \(\rho \cdot \frac{l / 2}{2 \mathrm{~A}}=\frac{1}{4} \rho \cdot \frac{l}{\mathrm{~A}}\) = \(\frac{1}{4}\) R1 = \(\frac{1}{4} \times 4\) = 1 Ω
Thus, the resistance of new wire is 1 Ω
Question 10.
Write the Joule’s law of heating. Also write the necessary formula for this. [2]
Answer:
(a) Joule’s Law of Heating:
When a current (I) flows through a resistor of resistance (R) for time (t), then the amount of heat produced (H) is given by
H = I2 x R x t
This is known as Joule’s law of heating.
The heat produced in the wire is directly proportional to:
square of current (I2)
resistance of wire (R)
time (t) for which current is passed.
Question 11.
The current-carrying solenoid when suspended freely rests along a particular direction. Why? [2]
Answer:
One end of the current-carrying solenoid acts like a north pole and the other end a south pole. So, if a current-carrying solenoid is suspended freely, it will come to rest pointing in the north and south direction (just like a freely suspended bar magnet).
Question 12.
When an iron knife is dipped in a solution of copper sulphate, a reddish-brown layer gets formed on the knife. Explain. [2]
Answer:
Iron is more reactive metal than copper and displaces it from its solution of copper sulphate. The reddish-brown layer seen on the knife is the deposit of displaced copper that is formed.
Question 13.
Why does the colour of copper sulphate solution change when an iron nail is dipped in it? [2]
Answer:
Iron is more reactive than copper. It displaces copper from copper sulphate solution according to the following reaction :
Thus, as copper sulphate reacts to form Iron(II) sulphate, the blue colour of copper of copper sulphate solution fades away.
Question 14.
Explain the meanings of malleable and ductile. [2]
Answer:
Malleab1e nature means that when a substance is beaten it forms a thin sheet. Most of the metals are malleable in nature. When a substance is drawn into thin wires it is called ductile. Gold is the most ductile metal.
Question 15.
What is ‘Thermite welding”? [2]
Answer:
The thermite welding process is the result of fusion created by chemical reaction that occurs due to the difference of free energy between aluminium and metal oxide. This difference produces enough heat to produce liquid steel or any other metal alloy without applying outside energy.
Question 16.
State two ways to prevent the rusting of iron. [2]
Answer:
Two ways to prevent the rusting of iron are:
(i) Oiling, greasing or painting: By applying oil, grease, or paint, the surface becomes waterproof and the moisture and oxygen in the air cannot come into direct contact with iron. Hence, rusting is prevented.
(ii) Galvanisation: An iron article is coated with a layer of Zinc metal, which prevents the iron to come in contact with oxygen and moisture. Hence, rusting is prevented.
Part-C
Long Answer Type Questions – Write the answer of questions 17 to 20 (Word limit 100 words)
Question 17.
Compare the functioning of alveoli in the lungs and nephrons in the kidney with respect to their structure and functioning. [3]
OR
What are the methods used by plants to get rid of excretory products? [3]
Answer:
Differences between alveoli and nephrons.
Alveoli | Nepbrons |
(i) Shape-Like bunches of grapes individual alveolus is a sac or balloon like structure. | (i) Shape – Nephron is tube-like with a cup-shaped mouth. |
(ii) Wall-Thin walled, just one cell thick. | (ii) Thin-walled, tube is just one cell thick. |
(iii) Blood supply- Highly vascular, richly supplied by blood capillaries. | (iii) Surrounded by capillaries. |
(iv) Surface area- Provide large surface area. | (iv) Due to long tubes of millions of nephrons large surface area. |
(v) Permeability- Permeable to gases. | (v) Permeable to water and small solute. |
(vi) Function Exchange of gases by diffusion to get oxygen and release out carbon dioxide. | (vi) Filtration of blood and selective reabsorption of filtrate to produce urine. |
Question 18.
Which plant was selected by Mendel for his breeding experiments? Why did Mendel choose the plant for his experiments? [3]
OR
What are homologous structures? Give an example. Is it necessary that homologous structures always have a common ancestor? Justify your answer.[3]
Answer:
Mendçl selected Garden pea (Pisum sativum) for his breeding experiments. Meridel selected pea plant for his experiment because:
- It has distinct and easily detectable alternate forms (contrasting forms) of many traits. For example, in seed colour trait there were two distinct forms yellow and green.
- It is self-pollinated in nature but can be cross-pollinated easily.
- Easy to grow, comparatively short life cycle, and produces many seeds which can be taken as representatives of the next generation.
Question 19.
Draw a labelled diagram of an electric motor. Explain the principle of DC motor. [3]
OR
Draw a labelled diagram of AC generator. Explain the principle of AC generators. [3]
Answer:
Question 20.
Balance the following chemical equations : 3
(a) HNO3 + Ca(OH)2 → CaNO3 + H2O
(b) NaOH + H2O4 → Na2SO4 + H2O
(c) NaCl + AgNOg > AgCl + NaNOs
OR
Write the balanced chemical reaction for the following : [3]
(a) Calcium hydroxide + Carbon dioxide > Calcium carbonate + Water
(b) Zinc + Silver nitrate > Zinc nitrate + Silver
(c) Aluminium + Copper chloride > Aluminium chloride + Copper
Answer:
(a) 2HNO3 + Ca(OH)2 → Ca(NO3)2 + 2H2O
(b) 2NaOH + H2SO4 → Na2SO4 + 2H2O
(c) NaCl + AgNO3 → AgCl + NaNO3
Part-D
Essay Type Questions – Write the answers of question 21 to 23 (Word limit 250 words)
Question 21.
(i) Explain hydrotropism.
(ii) Design an experiment to demonstrate hydrotropism. Draw labelled diagram. [4]
OR
(i) Why is adrenaline called as emergency hormone?
(ii) What are the effects of its secretion is excess on our body?
(iii) Why are some patients of diabetes treated by giving injections of insulin? [4]
Answer:
(i) Hydrotropisna: The growth movements in response to stimulus of water are known as hydrotropism. The roots are positively hydrotropic. It means that to get water roots move away from gravitational pull.
(ii) Hydrotropism can be demonstrated by following simple experiment: Two glass troughs A and B are filled with soil. For this purpose large size troughs are taken. In first through a small seedling is planted. A similar, equally healthy seedling is planted in second trough also. But in this trough, before planting the seedling, a small clay pot is also placed beneath the soil surface. This pot is filled with water.
Demonstration of Hydrotropism:
The plant of first trough (a) is watered daily. But no water is given to plant of second trough
(b) Such set-up is left as such for few days.
After a few days when we dig up two seedlings carefully, we notice that the roots of the plant A are straight. The root of second plant is found bent towards the pot of water.
This experiment clearly demonstrates that the roots are positively hydrotropic. This also proves that hydrotropism is
stronger than geotropism.
Question 22.
(i) Draw ray diagrams and show the nature of images formed in the following cases, when
(a) an object is placed between F and 2F infront of concave lens.
(b) an object is placed between F and 2F infront of convex lens.
(ii) An object 50 cm high is placed on the principal axis of a convex lens. Its 20 cm tall image is formed on the screen placed at a distance of 10 cm from the lens. Calculate the length of the lens. [4]
OR
Draw ray diagrams showing the image formation by a concave mirror when an object is placed : [4]
(a) between pole and focus of the mirror.
(b) between focus and centre of curvature of the mirror.
(c) at centre of curvature of the mirror.
(d) a little beyond centre of curvature of the mirror.
Answer:
(ii) Given, for a convex lens
h1= 50 cm,
h2 = -20 cm,
u = 10cm
As, m = \(\frac{h_{2}}{h_{1}}=\frac{v}{u}\)
u = \(\frac{h_{1}}{h_{2}} \times v=\frac{50}{-20} \times 10\)
u = -25cm
From lens formula
\(\frac{1}{f}=\frac{1}{v}-\frac{1}{u}=\frac{1}{10}-\frac{1}{(-25)}\)
\(\frac{1}{f}=\frac{5+2}{50}=\frac{7}{50} \)
f= 7.14 cm
Question 23.
(i) Write short note on water of crystallisation.
(ii) How is plaster of paris prepared? Give chemical reaction.
(iii) Write any two uses of it. [4]
OR
(i) Write electron dot structure of Ca and O.
(ii) Show the formation of calcium oxide by transfer of electrons. [4]
Answer:
(i) Water of Crystallisation: Water of crystallisation is the fixed number of water molecules present in one formula unit of a salt. Five water molecules are present in one firmula unit of Copper Sulphate (CuSO4.5H2O). Two
water molecules are present in one formula unit of gypsum (CaSO4.2H2O). And 10 water molecules are present in sodium carbonate (Na2CO3. 10H2O).
(ii) Plaster of Paris: On heating gypsum at 373 K, it loses water molecules and becomes Calcium Sulphate hemihydrate (CaSO4\(\frac{1}{2}\) H2O). This is called Plaster of Paris.
Plaster of Paris is a white powder and on mixing with water, it changes to gypsum once again giving a hard solid mass.
(iii) Uses of Plaster of Paris:
- It is used for making toys, materials for decoration and for making surfaces smooth.
- It is used as plaster for supporting fractured bones.
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