RBSE 10th Science Model Paper Set 5 with Answers in English

Students must start practicing the questions from RBSE 10th Science Model Papers Set 5 with Answers in English Medium provided here.

RBSE Class 10 Science Model Paper Set 5 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 breakdown of pyruvate to give carbon dioxide, water and energy takes place in: [1]
(a) cytoplasm
(b) mitochondria
(c) chloroplast
(d) nucleus
Answer:
(b) mitochondria

(ii) A few drops of iodine solution were added to rice water. The solution turned blue-black in colour. This indicates that rice water contains: [1]
(a) complex proteins
(b) simple proteins
(c) fats
(d) starch
Answer:
(d) starch

(iii) Posture and balance of the body is controlled by: [1]
(a) cerebrum
(b) cerebellum
(c) medulla oblongata
(d) pons varolii
Answer:
(b) cerebellum

(iv) ………………… promotes cell division: [1]
(a) auxin
(b) gibberellins
(c) cytokinins
(d) abscisic Acid
Answer:
(c) cytokinins

(v) A light ray enters from medium A to medium B as shown in figure. The refractive index of medium A relative to B will be: [1]

(a) greater than unity
(b) less than unity
(c) equal to unity
(d) zero
Answer:
(a) greater than unity

(vi) Which of the following can make a parallel beam of light when light from a point source is incident on it ? [1]
(a) concave mirror as well as convex lens
(b) convex mirror as well as concave lens
(c) two plane mirrors placed at 90° to each other
(d) concave mirror as well as concave lens
Answer:
(a) concave mirror as well as convex lens

(vii) One Board of Trade Unit is equivalent to : [1]
(a) 3.6 × 10⁶ joule
(b) 3.6 × 10⁵ joule
(c) 3.6 × 10⁷ joule
(d) 3.6 × 10⁴ joule
Answer:
(a) 3.6 × 10⁶ joule

(viii) If potential difference is doubled across the wire, the current: [1]
(a) gets halved
(b) gets no change
(c) gets doubled
(d) gets four times
Answer:
(c) gets doubled

(ix) Magnetic lines of force due to a bar magnet are very similar to that of a: [1]
(a) current carrying straight wire
(b) solenoid
(c) two parallel wires
(d) none of these
Answer:
(b) solenoid

(x) The following reaction is an example of a: [1]
Na₂SO₄ + BaCl₄ → BaSO₄ + 2NaCl
(a) decomposition reaction
(b) double displacement reaction
(c) combination reaction
(d) displacement reaction
Answer:
(b) double displacement reaction

(xi) A solution reacts with crushed egg-shells to give a gas that turns lime-
water milky. The solution contains: [1]
(a) NaCl
(b) HCl
(c) LiCl
(d) KCl
Answer:
(b) HCl

(xii) An element reacts with oxygen to give a compound with a high melting point. This compound is also soluble in water. The element is likely to be: [1]
(a) calcium
(b) carbon
(c) silicon
(d) iron
Answer:
(a) calcium

2. Fill in the blanks:

(i) ………………….. is called an emergency hormone because it prepares our body to fight emergency. [1]
Answer:
Adrenaline

(ii) …………………….. is the movement of water molecules from a dilute solution to a
concentrated solution through a semipermeable membrane. [1]
Answer:
Osmosis

(iii) Arabarf forests of Bengal are dominated by …………………….. . [1]
Answer:
Sal

(iv) Instead of ordinary bulb use …………………… light. [1]
Answer:
Fluorescent

(v) A concave mirror forms ………………….. , erect and magnified image of our face. [1]
Answer:
Virtual

(vi) Practical unit of power is …………………….. .[1]
Answer:
Horse power

3. Very Short Answer Type Questions (Answer the questions in one word or in one line)

(i) What makes the red blood cell red ? [1]
Answer:
Haemoglobin

(ii) What are gustato receptors ? [1]
Answer:
Taste receptors are called gustato receptor

(iii) What is the ultimate source of energy for an ecosystem ? [1]
Answer:
The sun,

(iv) Name the dam built on the river Narmada. [1]
Answer:
Sardar Sarovar Dam

(v) To which state of our country would you associate the khejari tree? [1]
Answer:
Rajasthan

(vi) What is the SI unit of charge ? [1]
Answer:
Coulomb

(vii) Name the rule which is used to find the direction of magnetic field due to a circular coil ? [1]
Answer:
Right hand thumb rule

(viii) What is a natural magnet ? [1]
Answer:
Natural magnet is an iron ore called magnetite

(ix) What colour change would you observe in red litmus with aqueous Magnesium hydroxide ? [1]
Answer:
Red litmus turns blue

(x) Write the two components of baking powder. [1]
Answer:
The main components of baking powder are sodium bicarbonate (NaHCO₃) and small amount of starch

(xi) What are the bases which are soluble in water called ? [1]
Answer:
Alkalies

(xii) Name the acid present in ant sting and give its chemical formula. [1]
Answer:
Methanoic acid (HCOOH)

Part – B

Short Answer Type Questions – Write the answer of questions no. 4 to 16 (Word limit 50 words)

Question 4.
What are the necessary conditions for autotrophic nutrition and what are its by-products ? [2]
Answer:
In autotrophic nutrition green plants make their food in the process of photosynthesis. This food is prepared from simple inorganic raw materials.
The requirement for autotrophic nutrition are:

• raw materials like carbon dioxide and water,
• green-coloured pigment chlorophyll for trapping energy (present in chloroplast).
• source of energy-sunlight.

Question 5.
What are the different ways in which individuals with a particular trait may increase in a population ? [2]
Answer:
The ways which may increase the individuals of a particular trait in a population are:

• Natural Selection (Directional selection)-Atype of natural selection in which an extreme (a particular) trait is selected. If a trait has survival advantage it is selected.
• Genetic Drift-A change in frequency of some genes of a small population by chance is called genetic drift.
• If the gene flow stops due to geographical isolation.

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.
What are the advantages of cloth bags over plastic bags during shopping ? [2]
Answer:
Advantages of cloth bags over plastic bags are-

• Cloth bags do not pollute the environment. Too much use of plastic has , damaged our environment.
• Cloth bags are stronger and more durable in comparison to plastic bags.
• They can be reused easily and hence, provide a good solution to the problem of accumulation of non-biodegradable plastic.
• Production as well as disposal of plastic cause pollution. Cloth bags do not cause any type of pollution and are eco-friendly.

Question 8.
Move the spoon slowly away from your face. Observe the image. How does it change ? [2]
Answer:
When the face is far away from the spoon a highly diminished, inverted image of our face forms at the focus of spoon.

Question 9.
A battery of 9 V is connected in series with resistors of 0.2 Ω, 0.3 Ω, 0.4 Ω,0.5Ω and 12 Ω respectively. How much current would flow through the 12 Ω resistor ? [2]
Answer:
Equivalent resistance of the resistors connected in series
R_s 0.2 Ω + 0.3 Ω + 0.4 Ω + 0.5 Ω + 12 Ω
= 13.4 Ω
Current through the circuit,
I = \(\frac{\mathrm{V}}{\mathrm{R}_{s}}=\frac{9 \mathrm{~V}}{13.4 \Omega}\) = 0.67 A
In the series circuit, the same current flows through all’ resistors, hence current flowing through 12 Ω resistor, = 0.67 A

Question 10.
Define electric potential difference and write its SI unit of it. [2]
Answer:
We can define, “Potential as the quantity which determines the direction of flow of charge between two points.
Electric potential difference between two points is the amount of work done in moving a unit positive charge from one point to another point. SI unit of potential difference is Volt.

Question 11.
Write the names of four devices where current-carrying conductor is used along with magnetic fields. [2]
Answer:
Devices that use currentcarrying conductor and magnetic fields are:

1. Electric motor,
2. Loud speakers,
3. Electric generators,
4. Microphone

Question 12.
Why should a magnesium ribbon be cleaned before burning in air ? [2]
Answer:
When magnesium ribbon remains in air it gets covered with a white layer of magnesium oxide. Hence, first of all, we should remove this layer by rubbing with sand paper before burning it in air.

Question 13.
State the kind of chemical reactions in the following examples :
(i) Digestion of food in stomach
(ii) Combustion of coal in air [2]
Answer:
(i) Decomposition reactions, because during digestion, the complex food is broken into simpler form.
(ii) Exothermic decomposition reaction. Coal burns in air to form CO2, H2O along with the evolution of heat.

Question 14.
A metal that exists as a liquid at room temperature is obtained by heating its sulphide in the presence of air. Identify the metal and its ore and give the reaction involved. [2]
Answer:
Metals, low in activity series can be obtained by reducing their sulphides or oxides, by heating. Mercury is the only metal that exists as liquid at room temperature. It can be obtained by heating cinnabar (HgS), the sulphide ore of mercury.
The reactions are as follows:

Question 15.
Write chemical equations for reactions taking place when :
(i) sodium oxide absorbs moisture (water) from atmosphere.
(ii) steam is passed over red hot iron. [2]
Answer:

Question 16.
What chemical process is used for obtaining a metal from its oxide ? [2]
Answer:
The chemical process used for obtaining a metal from its oxide is reduction. In this process metal oxides are reduced by using suitable reducing agents such as carbon or by highly reactive metals to displace the metals from their oxides.
For example: Zinc oxide is reduced to metallic zinc by heating with carbon.

Manganese dioxide is reduced to Manganese by treating it with aluminium powder. In this case, aluminium displaces manganese from its oxide.

Oxides of more reactive metals are reduced by electrolysis.

Part – C

Long Answer Type Questions – Write the answers of questions 17 to 20 (Word limit 100 words)

Question 17.
Draw a labelled diagram of external structure of a human heart. Write the functions of the heart. [3]
OR
Draw a labelled diagram of the respiratory system of human being. How is oxygen and carbon dioxide transported in human being ? [3]
Answer:

• To receive oxygenated blood from the lungs. Blood is oxygenated in the lungs.
• To pump this oxygenated blood to all parts of the body.
• To receive deoxygenated blood from all parts of our body (in body cells the blood gets deoxygenated due to cellular respiration. It means it picks up carbon dioxide from there)
• To send this received deoxygenated blood to lungs for purification. To do all this work efficiently the heart has chambers to prevent mixing of two types of blood. There are four chambers in heart. The upper two chambers are called atria.

Question 18.
(a) What is genetics ?
(b) What are genes ? Where are the genes located ? [3]
OR
What is meant by speciation ? List four factors that could lead to speciation. Which of these cannot be a major factor in the speciation of a self-pollinating plant species ? Give reason to justify your answer. [3]
Answer:
(a) Genetics is a branch of biology concerned with the study of genes, genetic variation and heredity in organisms. In other words, genetics is the scientific study of the way that the development of living things is controlled by qualities that have been passed from parents to children.

(b) Genes are units of heredity which transfer characteristics (or traits) from parents to their offsprings during reproduction. A gene is a unit of DNA on a chromosome which governs the synthesis of one protein that controls a specific characteristics of an organism.

Question 19.
(a) What is an electromagnet ? List any two uses.
(b) Draw a labelled diagram to show how an electromagnet is made.
(c) State the purpose of soft iron core used in making an electromagnet. [3]
OR
Explain the working of an electric generator by drawing a labelled diagram. [3]
Answer:
(a) A electromagnet is a magnet consisting of a long coil of insulated copper wire wrapped around a soft iron core that is magnetised only when electric current is passed through the coil.
Uses: Electric bells, magnetic levitation, etc.
(b) Diagram, to show how
an electromagnet is made :

(c) The core of an electromagnet must be soft iron because soft iron loses all of its magnetism when current in the coil is switched off.

Question 20.
Write the balanced chemical equations for the following statements :
(i) NaOH solution is heated with zinc granules.
(ii) Excess of carbon dioxide gas is passed through lime water.
(iii) Dilute sulphuric acid reacts with sodium carbonate. [3]
OR
What kind of chemical reactions are the following :
(i) Cu(s) + 4HNO₃(aq) → Cu(N0₃)₂ (aq) + 2NO₂(g) + 2H₂O(l)
(ii) Cu(NO₃)₂(aq) + 2NaOH(aq) → Cu(OH)₂(s) + 2NaNO₃(aq)
(iii) HNO₃(aq) + NaOH(aq) → H₂O(Z) + NaNO₃(aq) [3]
Answer:
(i) 2NaOH(aq) + Zn(s) → Na₂ZnO₂(ag) + H₂(g)

(ii) Ca(OH)₂ + CO₂ → CaCO₃(s) + H₂O

CaCO₃(s) + CO₂(g) + H₂O(l) → CaCHCO₃(aq)

(iii) H₂SO₄(dil) + Na₂CO₃(s) → Na₂SO₄ + CO₂ + H₂O

Part – D

Essay Type Questions – Write the answers of question 21 to 23 (Word limit 250 words)

Question 21.
How are involuntary actions and reflex actions different from each other [4]
OR
(i) What are the major parts of the brain ?
(ii) Mention the function of its different parts. [4]
Answer:
The reflex actions are fast automatic, involuntary actions. They are involuntary because they are not ip our conscious control. Reflex actions are response of our body to external stimuli. These stimuli may be light (constriction of pupil of eye), chemicals (sneezing), etc. Involuntary actions are continuous involuntary response of our body to internal stimuli. When food reaches our stomach gastric juice is secreted, without any conscious process. Breathing, beating of heart are all involuntary actions. Involuntary actions are controlled by autonomic nervous system. (It must be kept in mind that for all muscular actions stimuli are must. Muscles contract only when they are stimulated). Reflex action often involves voluntary muscles as effector organ while involuntary actions involve involuntary muscles.

Question 22.
Explain the convention of symbols for spherical mirror. An object 5 cm in length is held 25 cm away from a converging lens of focal length 10 cm. Draw the ray diagram and find the position, size and the nature of the image formed. [4]
OR
An object of height 4.0 m is placed at a distance of 30 cm from the optical centre ‘O’ of a convex lens of focal length 20 cm. Draw a ray diagram to find the position and size of the image formed. Mark optical centre ‘O’ and principal focus ‘F’ on the diagram. Also, find the approximate ratio of size of the image to the size of the object. [4]
Answer:
(i) All distances are measured from the pole.

(ii) Distances measured in the direction of incident rays are taken as positive while in the direction opposite of incident rays are taken as negative.
(iii) Distances above the principal axis are taken positive and below the principal axis are taken negative.

Question 23.
(a) Identify the acid and the base whose combination forms the common salt that you use in your food. Write its formula and chemical name of this salt. Name the source from where it is obtained.
(b) What is rock salt ? Mention its colour and the reason due to which it has this colour. [4]
OR
A student dropped few pieces of marble in dilute hydrochloric acid, contained in a test tube. The evolved gas was then passed through lime water. What will happen if excess of gas is passed though lime water ? [4]
Answer:
(a) HCl is acid and NaOH is base whose combination forms the common salt. Its formula is NaCl (Sodium Chloride). It is obtained from sea water.
(b) Rock salt is the common name for the mineral ‘halite’. Its chemical formula is NaCl. It may be white or light blue or yellow depending upon impurities present in it.