RBSE 10th Science Board Model Paper 2022 with Answers in English 

Students must start practicing the questions from RBSE 10th Science Model Papers Board Model Paper 2022 with Answers in English Medium provided here.

RBSE Class 10 Science Board Model Paper 2022 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 phloem in plants are responsible for the :
(a) transport of food
(b) transport of water
(c) carrying oxygen
(d) carrying amino acid [1]
Answer:
(a) transport of food

(ii) The stomach in human being is a part of a system for :
(a) respiration
(b) excretion
(c) nutrition
(d) transportation [1]
Answer:
(c) nutrition

(iii) Which of the following is a plant hormone?
(a) gibberellins
(b) estrogen
(c) insulin
(d) thyroxin [1]
Answer:
(a) gibberellins

(iv) Which hormone activates the cell division :
(a) abscisic acid
(b) testosterone
(c) auxins
(d) cytokinin [1]
Answer:
(d) cytokinin

(v) In a convex lens, the point at which the incident ray passes straight without bending is known as :
(a) point of focus
(b) aperture
(c) optical center
(d) center of curvature [1]
Answer:
(c) optical center

(vi) The correct relation between the angle of incidence (i) and the angle of reflection (r) is:
(a) i = r
(b) i > r
(c) i < r
(d) i ≠ 1
Answer:
(a) i = r

(vii) Instrument of measuring the potential difference is :
(a) galvanometer
(b) voltmeter
(c) ammeter
(d) ohmmeter [1]
Answer:
(b) voltmeter

(viii) Resistance of conducting wire depends on:
(a) on its length
(b) on its area of cross-section
(c) on its temperature
(d) all of these [1]
Answer:
(d) all of these

(ix) The device which converts the electrical energy into mechanical energy is known as:
(a) generator
(b) electric motor
(c) voltmeter
(d) ammeter [1]
Answer:
(b) electric motor

(x) Reaction Fe₂O₃ + 2Al → Al₂O₃ + 2Fe, is an example of a :
(a) combination reaction
(b) Double displacement reaction
(c) decomposition reaction
(d) Displacement reaction [1]
Answer:
(d) Displacement reaction

(xi) Which one of the following types of medicines is used to treat indigestion?
(a) antibiotic
(b) analgesic
(c) antacid
(d) antiseptic [1]
Answer:
(c) antacid

(xii) Food cans are coated with tin and not with zinc because :
(a) zinc is more expensive than tin
(b) zinc has a higher melting point than tin
(c) zinc is more reactive than tin
(d) zinc is less reactive than tin [1]
Answer:
(c) zinc is more reactive than tin

2. Fill in the blanks:

(i) The secretion of ……………………………. hormone occurs in males. [1]
Answer:
testosterone

(ii) Waste by-products removed from the body, this process is called as ……………………………….. . [1]
Answer:
excretion

(iii) Ozone layer protects against the ………………………… from the sun. [1]
Answer:
ultraviolet rays

(iv) The example of ………………………….. fuel are coal and petroleum. [1]
Answer:
fossil

(v) Half the distance between the pole and the center of curvature of the spherical mirror is called ……………………….. . [1]
Answer:
focal length

(vi) The unit of electric power is …………………………. . [1]
Answer:
watt

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

(i) In which part of the body is digested food absorbed? [1]
Answer:
The digested food is absorbed by the wall of intestine.

(ii) Diabetes is caused by deficiency of which hormone? [1]
Answer:
Diabetes is caused by the deficiency of hormone insulin.

(iii) Which chemical is used in refrigerator? [1]
Answer:
Chloro Fluoro Carbon (CFCs) is used in refrigerator.

(iv) ‘Amrita Devi Bishnoi National Award’ is related to? [1]
Answer:
‘Amrita Devi Bishnoi National Award’ is related to wildlife conservation.

(v) Write the Dam name on the river Ganga. [1]
Answer:
Tehri Dam.

(vi) If resistance of at conductor wire of length l is RΩ. What will be the length of same conducting wire to obtain 2RΩ resistance? [1]
Answer:
2l

(vii) Why two magnetic field lines don’t intersect each other? [1]
Answer:
If two magnetic lines of force intersect each other, then there would be two directions of the magnetic field at one point, which is not possible.

(viii) Which electrical device do we use to know whether current is flowing in a circuit or not and in which direction? [1]
Answer:
Galvanometer.

(ix) Which sodium compound is used to softening hard water? [1]
Answer:
Sodium Carbonate Decahydrate (Washing Soda-Na₂CO₃.10H₂O

(x) The pH value of fresh milk is 6. How do you think the pH will change as it turns into curd? Explain your answer. [1]
Answer:
pH of milk falls below 6 as it turns into curd due to the formation of lactic acid from lactose.

(xi) Why is distilled water not a conductor of electricity while rainwater is? [1]
Answer:
Rainwater contains ions of acids so it conducts electricity whereas there are no ions in distilled water.

(xii) What is the common name of compound CaOCl₂. [1]
Answer:
Bleaching Powder.

Part-B

Short Answer Type Questions – Write the answer of questions 4 to 16 (Word limit 50 words)

Question 4.
What is the role of saliva in the digestion of food? [2]
Answer:
Saliva is a watery fluid which contains salivary amylase enzyme and mucus.
Saliva moistens and softens the food. Its amylase enzyme converts the starch of the food into a sugar maltose.

Question 5.
Explain the traits of dominant and recessive? [2]
Answer:
In Mendel’s experiment with pea plants, when he crossbred a tall pea plant with a short pea plant, he found that the first generation (F₁) was of only tall plants. In the F₁ progeny, no short plants were obtained. In the F₂ progeny, both traits tallness and shortness were inherited where the tall character was the dominant trait and short character was the recessive trait.

Question 6.
Write the phenotypic ratio of monohybrid and dihybrid. [2]
Answer:
Phenotypic ratio of monohybrid-3: 1
Phenotypic ratio of dihybrid-9 : 3 : 3: 1

Question 7.
What is called biodegradable? [2]
Answer:
Organic substances which are broken down in nature by microbes into simpler inorganic substances that can be recycled are called biodegradable.

Question 8.
Write the laws of refraction of light. [2]
Answer:

• First law of refraction-The incident ray, refracted ray, and the normal at the point of incidence, all lie in the same plane.
• Second law of refraction-The ratio of the sine of file angle of incidence to the sine of the angle of refraction is constant and equal to the refractive index of that medium.

This law is also called Snell’s law.
Refractive index (n) = \(\frac{\text { sine of angle of incidence }}{\text { sine of angle of refraction }} \)
⇒ n = \(\frac{\sin i}{\sin r}\) = constant.

Question 9.
If three resistors 2Ω, 3Ω & 6Ω are connected in parallel, then calculate the equivalent resistance of this combination. [2]
Answer:
(b) Since, resistances are connected in parallel, so
\(\frac{1}{R}=\frac{1}{2}+\frac{1}{3}+\frac{1}{6}\)
⇒ \(\frac{1}{R}=\frac{3+2+1}{6}\)
⇒ \(\frac{1}{R}=\frac{6}{6}\)
⇒ R = 1 Ω

Question 10.
Write the Ohm’s law for an electric circuit. Also, write the necessary formula for it. [2]
Answer:
Ohm’s law states that the current flowing through a conductor is directly proportional to the potential difference across the ends of the wire at constant physical conditions like temperature, pressure etc. Let T be the current flowing through a conductor and V is the potential difference across the ends of the conductor, then
V∝I

Question 11.
Write down the Fleming’s Left Hand Rule and draw the necessary diagram to explain the direction of force acting on it when a current-carrying rod is placed vertically in a magnetic field. [2]
Answer:
Fleming’s Left-Hand Rule: Stretch your thumb, middle finger, and forefinger of left hand such that they are mutually perpendicular, then thumb gives direction of force (F), forefinger gives direction of magnetic field (B) and middle finger would give direction of current (I).

Question 12.
Why do we paint iron objects? [2]
Answer:
Paint covers the surface of the iron particles. Hence, moist air cannot react with iron, and this prevents rusting.

Question 13.
What is a balanced chemical equation? Why is it necessary to balance a Chemical Equation? [2]
Answer:
The chemical equation in which the number of atoms of each element on both sides of the equation are equal is called a balanced chemical equation.
For example : 2H₂ + O₂ → 2H₂O
A chemical equation should be balanced because there is no loss or gain of any matter during a chemical reaction, i.e. the law of conservation of mass must hold good for the reaction.

Question 14.
Why do ionic compounds have high melting points? [2]
Answer:
Ionic compounds have strong electrostatic forces of attraction between the ions. Therefore, it requires a lot of energy to overcome these forces. That is why ionic compounds have high melting points.

Question 15.
Draw labelled diagram of electrolytic refining of copper? [2]
Answer:

Question 16.
Explain by experiments that metals are good conductors of heat; also draw the required diagram. [2]
Answer:

Once the candle is lit, hold the metal rod by pointing its one end on the flame of the candle within a few second or minute, you will feel the heat at the other end of the rod, and after some time the rod get very hot. The simple experiment proves that metals are good conductors of heat.

Part-C

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

Question 17.
What is the difference between aerobic and anaerobic respiration? [3]
OR
What will be the consequences of deficiency of hemoglobin in our body? [3]
Answer:

Aerobic Respiration	Anaerobic Respiration
1. It takes place in the presence of oxygen.	1. It takes place in the absence of oxygen.
2. Complete breakdown of glucose or food occurs.	2. Partial or incomplete breakdown of food.
3. End products are CO2 + water.	3. In yeast ethanol and CO2 are produced. In animals, end product is lactic acid.
4. Large amount of energy is released.	4. Small amount of energy is released.

OR

Hemoglobin is the respiratory pigment that transports oxygen to the body cells for cellular respiration. Therefore, deficiency of hemoglobin in the blood can affect the oxygen-supplying capacity of the blood. This can lead to a deficiency of oxygen in the body cells. It can also lead to a disease called anemia. The average hemoglobin content of blood, irrespective of sex, is 14.5 gm per 100 mL.

Hemoglobin is a protein in red blood cells that is made up of four chains. Each of these chains contains a compound known as heme, which contains iron, which transports oxygen in the bloodstream. Hemoglobin functions by binding and transporting oxygen from the lungs’ capillaries to all tissues in the body. It also plays a role in transporting carbon dioxide from the body’s tissues back to the lungs.

• A low hemoglobin level is referred to as anaemia.
• Conditions in which haemoglobin has an abnormal structure include Sickle cell anaemia. An inherited condition in which the abnormal haemoglobin results in RBC’s shaped like sickles. They can get ‘stuck’ in blood vessels, resulting in several problems and thalassemia.
• Normal haemoglobin levels vary by age and sex. They’re measured in grams per decilitre (g/dL).
• Adult male: 13.8-17.2 g/dL
• Adult female: 12.1-15.1 g/dL.

Question 18.
Explain the terms homologous and analogous organs with diagram. [3]
OR
Explain fossils with diagram. [3]
Answer:
Homologous Organs: These organs which have the similar basic structure but different functions are known as homologous organs. The forelimbs of vertebrate animals, like forelimb of a human being, forelimb of a bird, flipper of a whale, forelimb of a horse are very good examples of homologous organs.

Analogous Organs
The organs which have different basic structural design but perform similar functions are called analogous organs.
Some organs of different animals are similar in appearance and perform similar function but their basic structure is different. For example, the wings of a bird and wings of a bat are similar in appearance. They help these animals in flying, and this perform the same function. But their basic structure is quite different.

The remains or remnants of organisms of remote past are known as fossils. They may be in the form of a dead mineralised part or an impression etc. The fossils provide good evidence for establishing evolutionary relationships.
Generally, when organisms die, their body get decomposed. But in some cases the peculiar environment does not allow the body of an organism or a part of it to decompose.
mud around the organism will harden and retain the impression of the body parts of that insect or the leaf. This is how impression of organisms in a rock are formed. Sometimes the insect may be trapped in resin.

Question 19.
What do you understand by magnetic field? Write the characteristics of magnetic lines of force. Draw the necessary diagram to show the magnetic field produced by a current-carrying circular coil. [3]
OR

What is the working principle of an electric motor? Explain its working by drawing the necessary diagram. Write down two uses of electric motor. [3]
Answer:
The space around a magnet within which its influence can be experienced is called its magnetic field.
Characteristics of Magnetic Field :

• Magnetic lines of force are closed continuous curves or loops.
• No two lines of force are found to intersect each other.
• Inside the magnet, lines of force are from south to north whereas outside the magnet these are from north to south.
• Density of magnetic lines of force in a given region represents the relative strength of magnetic field.

Magnetic lines of Force due to circular coil:

Working: When a current enters into the coil in the direction SPQR then by the application of Fleming’s left hand rule we find that arm SP experiences a force acting downward and arm QR experiences a force acting upward. These forces are same in magnitude but their line of action is not same so they form a couple whose torque makes the coil to rotate in anticlockwise direction.

But when the coil completes half revolution the two commutator (half rings) automatically change contact from one brush to other and reverse the direction of current in coil along RQPS and in turn change the force. Now RQ experiences the force downward and arm PS experiences force upwards. In this way armature continues to rotate about its axis in anticlockwise direction. Rotation of the motor depends on many factors. It depends on the current through the armature, number of turns in the coil of armature, area of the coil and strength of magnetic field.

Uses:

• The uses of electric motor mainly include blowers, fans, machines, etc.
• The electric motor is an essential device in different application like HVAC-heating ventilating and cooling equipment, home appliances and motor vehicles.

Question 20.
Write the method of electrolysis of water. Give its essential chemical reaction and draw labelled diagram. [3]
OR
Why does the colour of copper solution change when an iron nail is dipped in a solution of copper sulphate? Explain by required diagrams. [3]
Answer:

Procedure

1. Take a plastic mug. Drill two holes at its base and fit rubber stoppers in these holes. Insert carbon electrodes in these rubber stoppers as shown in figure.
2. Connect these electrodes to a 6-volt battery.
3. Fill the mug with water such that the electrodes are immersed. Add a few drops of dilute sulphuric acid to the water.
4. Take two test tubes filled with water and invert them over the two carbon electrodes.
5. Switch on the current and leave the apparatus.
6. You will observe the formation of bubbles at both the electrodes. These bubbles displace water in the test tube.

Chemical reactions : 2H₂O → 2H₂ ↑ + O₂ ↑

OR

When an iron nail is immersed in copper sulphate solution, then iron displaces copper from the solution of copper sulphate because iron is more reactive than copper. Therefore copper sulphate solution colour changes from blue to pale green.

Reaction
CUSO₄ (aq) + Fe (s) → FeSO₄ (aq) + Cu (s)
In this reaction following two processes take place:
Cu²⁺ +2e = Cu° (reduction process, Cu²⁺ is the oxidizing agent)
Fe° – 2e = Fe²⁺ (oxidation process, Fe° is the reducing agent)
The reaction is a double displacement reaction as well as redox reaction (oxidation and reduction both take place simultaneously).

Explanation:
When an iron nail is dipped in copper sulphate solution, a brown coating of copper is formed in the surface of iron and the colour of copper sulphate solution changes from blue to pale green. The reaction shows that iron is more reactive than copper because it displaces copper from the copper sulphate solution. The iron passes into the solution as Fe (II) forming the ferrous sulphate solution.

Part-D

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

Question 21.
(i) What are synapses called?
(ii) What are the functions of a nerve cell (neuron)
(iii) Draw a labelled diagram of a neuron cell. [4]
OR
(i) Which part of the brain maintains the posture and balance of the body.
(ii) Write two examples of involuntary actions.
(iii) Draw a labelled diagram of the human brain. [4]
Answer:
(i) A synapse is a fine gap between two adjacent neurons through which nerve impulse is transmitted from one neuron to other in the form of a chemical impulse.

(ii) Neurons are the cells of the nervous system. Their function is (a) Dendrites detect the change of the environment (stimuli) (b) sensory neuron, to transmit this information to central nervous system in the form of nerve impulse or electrical impulse, (c) to interpret the message, (d) to transmit the message of central nervous system to effector organs again in the form of electrical impulses (motor neuron). Dendrites of a neuron collect information and transmit it to CNS through axons. Some neurons are adapted as special receptors.

(iii) Neuron Cell

OR

(i) The part of the brain responsible for maintaining posture and balance of the body is the Cerebellum.
Explanation:
This part of the brain appears to be a separate structure, distinct from the rest of the brain. It is located right below the cerebrum, which is made of two hemispheres. It is called a ‘little brain’. The cerebellum is also responsible for reveiving information from the sensory organs, the spinal cord, and other parts of the brain. It also regulates motor learning and movement.

Cerebellar cortex: A layer containing folded tissue containing most of the cerebellum’s neurons
Cerebellar nuclei: The innermost part of the cerebellum containing nerve cells that communicate information from the cerebellum.

(ii) Involuntary action:
Actions which take place without consciousness or willingness of an individual are called involuntary actions. Digestion, heart beat, sneezing, etc are few examples of involuntary actions.

(iii) Human Brain

Question 22.
Explain the convention of symbols for spherical lenses. The focal length of a concave lens is 15 cm. At what distance should an object be placed from the lens so that its image is formed at a distance of 10 cm from the lens. Also find the magnification produced by lens. Draw a ray diagram for the image formed by a convex lens when the object is placed between 2F₁ and F₁. [4]
OR
Using a concave mirror of focal length 15 cm, we , want to confirm an erect image of an object. What should be the range of distance of the object from the mirror. Write a note on the nature and size of the image. Draw a ray diagram of the image formation in this situation. The magnification produced by a mirror is + 1. What is its meaning?  [4]
Answer:
Cartesian Sign Convention for Spherical Lenses
(i) All distances in a lens are to be measured from optical center of the lens.
(ii) Distances measured in the direction of incident ray are taken to be positive.
(iii) Distance opposite to the direction of incident ray are taken to be negative.
(iv) The height of the object or image measured above the principal axis are taken positive whereas below it, are taken as negative.
A concave lens always forms a virtual, erect image on the same side of the object.
Image distance, ν = – 10 cm
Focal length f = – 15 cm
Object distance u = ?
Since, \(\frac{1}{v}-\frac{1}{u}=\frac{1}{f}\)
⇒ \(\frac{1}{u}=\frac{1}{v}-\frac{1}{f}\)
⇒ \(\frac{1}{u}=\frac{1}{-10}-\frac{1}{(-15)}=-\frac{1}{10}+\frac{1}{15}\)
⇒ \(\frac{1}{u}=\frac{-3+2}{30}=\frac{1}{-30}\)
⇒ u = -30 cm

Magnification, m = \(\frac{v}{u}=\frac{-10 \mathrm{~cm}}{-30 \mathrm{~cm}}=\frac{1}{3}\)
= + 0.33
(+ ve) sign shows that the image is erect and virtual. The image is one-third of the size of the object.

To obtain erect image of an object in a concave mirror, the object should be placed between pole and principal focus of the mirror.
Therefore, range of distance of the object from the mirror must be less than 15 cm. The image will be erect and virtual and size of the image would be larger than the size of the object.

Meaning of magnification + 1 produced by mirror :
The size of image and object is equal. The positive sign indicates that the image formed by a plane mirror is virtual and is formed opposite to the object.

Question 23.
Which gas is usually released when an acid reacts with a metal? Explain with an example how you will test for the presence of this gas. Draw required diagram. [1 + 2 + 1 = 4]
OR
Effervescence occurs when a metallic compound reacts with dilute hydrochloric acid. The gas produced by this extinguishes the burning candle. If one of the compounds produced is calcium chloride, then write the balanced chemical equation for this reaction. [1 + 2 + 1 = 4]
Answer:
Hydrogen gas is produced when an acid reacts with a metal.

Take about 5 ml of dilute sulphuric acid in a test tube and add a few pieces of zinc granules to it.
Bubbles are formed due to evolution of a gas. This gas bums with a pop sound which indicates that the gas evolved is hydrogen.

OR

When calcium carbonate reacts with hydrochoric acid, it produces carbon dioxide gas with effervescence. Carbon dioxide is used as fire extinguisher because it does not support combustion. Hence, it extinguishes a burning candle. Therefore, the metal compound A is calcium carbonate.
CaCO₃ + 2HCl → CaCl₂ + CO₂ + H₂O.