SSC Maharashtra Board Science 1 Question Paper Dec 2020 with Answers

Maharashtra Board SSC Class 10 Science 1 Question Paper Dec 2020 with Answers Solutions Pdf Download.

SSC Science 1 Question Paper Dec 2020 with Answers Pdf Download Maharashtra Board

Time: 2 Hours
Total Marks: 40

Note:

1. All questions are compulsory.
2. Use of a calculator is not allowed.
3. The numbers to the right of the questions indicate full marks.
4. In case of MCQs (Q. No. 1(A)) only the first attempt will be evaluated and will be given credit.
5. For each MCQ, the correct alternative (A), (B), (C) or (D) with subquestion number is to be written as an answer.
   For Eg.: (i) (A), (ii) (B), (iii) (C)
6. Scientifically correct, labelled diagrams should be drawn wherever necessary.

Question 1.
(A) Choose the correct option: [5]
i. The minimum velocity of the spacecraft to escape from earth’s gravitational force must be _________. (B)
(A) 112 km/s
(B) 11.2 km/s
(C) 1.12 km/s
(D) 0.112 km/s
Answer:
(B) 11.2 km/s

ii. The melting point of pure ethanoic acid is _________. (A)
(A) 17°C
(B) 19°C
(C) 15°C
(D) 27°C
Answer:
(A) 17°C

iii. The process of separation of light into its component colour while it is passing through a medium is called _________. (C)
(A) reflection
(B) refraction
(C) dispersion
(D) internal reflection
Answer:
(C) dispersion

iv. The conversion of ferrous sulphate into ferric sulphate is _________ reaction. (A)
(A) oxidation
(B) displacement
(C) electrolysis
(D) reduction
Answer:
(A) oxidation

v. Lithium (Li), ________ and potassium (K) is Dobereiner’s triad. (C)
(A) magnesium (Mg)
(B) aluminium (Al)
(C) sodium (Na)
(D) calcium (Ca)
Answer:
(C) sodium (Na)

(B) Solve the following sub-questions: [5]
i. State true or false:
The refractive index depends upon the velocity of light in medium.
ii. Write the correlated answer:
Torch : Concave lens :: Camera : ________ .
iii. Find odd man out:
Zinc, iron, phosphorus, sodium.
iv. Draw the structural formula of C3H8.
v. Which satellite is used in educational field among INSAT and GSAT series?
Answer:
i. True
ii. Torch : Concave lens :: Camera : Convex lens
iii. Phosphorus
Phosphorus is nonmetal while others are metals.
iv. The structural formula of propane, C₃H₈ is

v. EDUSAT satellite in the INSAT and GSAT series is used specially in the field of education.

Question 2.
(A) Give scientific reasons (any two): [4]
i. Star appears to be twinkling at night.
ii. Simple microscope is used for watch repairs.
iii. The copper vessels turn greenish and silver articles turn blackish when kept open in air for long time.
(B) Answer the following questions (any three): [6]
i. An object takes 5 seconds to reach the ground from a height of 5 m on a planet. What is the value of ‘g’ on that planet?
ii. Identify ‘A’ and ‘B’ from the following table and complete the table. Write the chemical equation:

iii. Write the modern periodic law and also give the names of ‘blocks’ in modern periodic table.
iv. Distinguish between ‘alternating current’ and ‘direct current’.
v. Define specific heat capacity. Write its S.I. unit.
Answer:
(A) i. a. Stars are point sources of light as they are very far away from us.
b. The apparent position of star is slightly higher than its actual position due to refraction of starlight from the atmosphere. The starlight travels from rarer medium to denser medium and continuously bends towards the normal.
c. Due to the motion of atmospheric air and change in density and temperature, the atmosphere is not steady. As a result, refractive index of air in given region changes continuously and randomly.
d. Hence, the apparent position of star and its brightness is not stationary but changes slightly.
e. In this way, due to change in refractive index of atmosphere, the stars appear twinkling at night.

ii. a. A magnification of about 20 times is obtained by simple microscope.
b. When an object is placed within the focal length of convex lens, one gets a magnified and erect image of the object.
c. Thus, the watch repairer can see the minute parts of the watch more clearly with the help of simple microscope than the naked eye, without any strain on the eye.
Hence, simple microscope is used for watch repairs.

iii. a. If copper vessels are kept in air for long time, greenish layer of copper carbonate is formed on its surface.
b. When silver ornaments are exposed to air for long time, they turn blackish due to formation of the layer of silver sulphide.

(B) i. Solution:
Given: Time (t) = 5 s, height (s) = 5 m
To find: Gravitational acceleration (g)
Formula: s = ut + \(\frac{1}{2}\)gt²
Calculation: From formula,

Ans: The gravitational acceleration of the planet is 0.4 m/s².

ii. a. The white solid ‘A’ is calcium oxide (CaO, quick lime) and gas ‘B’ is carbon dioxide (CO₂).

iii. a. Modern periodic law states that “The properties of elements are a periodic function of their atomic numbers.”
b. The entire periodic table is divided into four blocks:
1. s-block: contains group 1 and 2 elements
2. p-block: contains group 13 to 18 elements
3. d-block: contains group 3 to 12 elements (transition elements)
4. f-block: contains lanthanide and actinide series

iv.

Alternating current	Direct current
a. Alternating current varies in magnitude continuously. i.e., oscillatory.	Magnitude of direct current from a source remains same. i.e., non-oscillatory.
b. Direction reverses periodically, i.e., after equal intervals of time.	Direction remains same.
c. This type of current is used in electrical household appliances such as electric heater, refrigerator, electric iron, etc.	This type of current is not used much for household purposes but used in batteries, torches etc.
d. Frequency of A.C. in India is 50 Hz, i.e., its cycle changes in \(\frac{1}{50}\) second.	Frequency of D.C. is zero.
e. Produced by A.C. generator.	Produced by D.C. generator.

v. a. The amount of heat energy required to raise the temperature of a unit mass of an object by 1 °C is called the specific heat or specific heat capacity of that object.
b. SI unit of specific heat capacity is J/kg °C

Question 3.
Answer the following (any five): [15]
i. An iron ball of mass 3 kg is released from a height of 125 m and falls freely to the ground. Assuming that the value of ‘g’ is 10 m/s², calculate:
a. Time taken by the ball to reach the ground.
b. Velocity of the ball on reaching the ground.
ii. An element has its electron configuration as (2, 8, 2). Answer the following:
a. What is the ‘atomic number’ of this element?
b. What is the ‘Group’ of this element?
c. To which period does this element belong?
iii. a. Write the ‘endothermic’ or ‘exothermic’ nature of the reaction:

b. Balance the given chemical equation:
NaOH_(aq) + H₂SO_4(aq) → Na₂SO_4(aq) + H₂O_(l)
c. From given reaction, identify ‘oxidant’ and ‘reductant’:
CuO + H₂ → Cu + H₂O
iv. A copper sphere of 100 g mass is heated to raise its temperature to 100°C and is released in water of mass 195 g and temperature 20°C in a copper calorimeter. If the mass of the calorimeter is 50 g, what will be the maximum temperature of water?
(Specific heat of copper = 0.1 cal/g°C)
v. a. Draw a neat labelled diagram of ‘dispersion of white light through glass prism’.
b. Which coloured ray is the least deviated?
c. Which coloured ray is the most deviated?
vi. Complete the following table for convex lens:

vii. Observe the following diagram and answer the questions:

a. Write the ‘anode reaction’.
b. Write the ‘cathode reaction’.
c. What is the purpose of mixing ‘cryolite’ and ‘fluorspar’ with ‘alumina’ in the electrolytic reduction of alumina?
viii. a. What is the principle behind the working of satellite launch vehicle?
b. Write the formula for the escape velocity.
c. Write the long form of ‘ISRO’.
Answer:
i. Solution:
Given: Mass (M) = 3 kg, height (s) = 125 m, u = 0,
gravitational acceleration (g) = 10 m/s²
To find: i. Time taken (t)
ii. Final velocity (v)

Ans: i. The iron ball will take 50 s to reach the ground.
ii. Velocity of the ball on reaching the ground will be 50 m/s.

ii . Atomic number of the element is 12.
b. The element belongs to group 2.
c. The element belongs to period 3.

iii. a. The reaction is endothermic.
b. 2NaOH_(aq) + H₂SO_4(aq) → Na₂SO_4(aq) + 2H₂O_(l)
c. Oxidant: CuO
Reductant: H₂

iv. Solution:
Let copper sphere, water and calorimeter attain final temperature T °C.
We have,

Heat lost by copper sphere
Q = m_sphere × c_sphere × ∆T = 100 × 0.1 × (100 – T)
Heat gained by water in calorimeter
Q₁ = m_water × c_water × ∆T’ = 195 × 1 × (T – 20)
Heat gained by calorimeter
Q₂ = m_calorimeter × c_calorimeter × ∆T = 50 × 0.1 × (T — 20)
According to principle of heat exchange,
Q = Q₂ + Q₂
∴ 10 × (100 – T) = 195 × (T – 20) + 5 × (T — 20)
∴ 1000 – 10T = 200(T — 20)
∴ 210 T = 5000
∴ T ≈ 23.8 °C
Ans: Maximum temperature of water will be 23.8 °C.

v. a.

b. Red coloured ray deviates the least during the dispersion of light through a prism.
c. Violet coloured ray deviates the most during the dispersion of light through a prism.

vi.

vii. a. Anode reaction: 2O^2- → O₂ + 4e^–
b. Cathode reaction: Al³⁺ + 3e^– → Al_(l)
c. Alumina has a very high melting point (>2000 °C). The purpose of mixing ‘cryolite’ and ‘fluorspar’ with ‘alumina’ in the electrolytic reduction of alumina is to carry out the process at a much lower temperature. Addition of cryolite and fluorspar reduces the melting point of alumina to about 1000 °C.

viii. a. The working of satellite launch vehicle is based on Newton’s third law of motion.

b. The formula for escape velocity is,
V_esc = \(\sqrt{\frac{2 \mathrm{GM}}{\mathrm{R}}}\)
where, G : Gravitational constant, M : Mass of the planet,
R : Radius of the planet,

c. Long form of ISRO is Indian Space Research Organization.

Question 4.
Solve the following questions (any one): [5]
i. Observe the diagrams and answer the questions:

a. Which effect of electric current is shown in the above figure?
b. What will happen if the number of electric cells is increased on the magnetic needle?
c. If the distance between the conductor and magnetic needle is increased, what will be the effect on intensity of magnetic field?
d. If the ends of electric cell are interchanged, what will be the effect of the magnetic needle?
e. Write the names of any two instruments which work on magnetic effect of electric current.
ii. Answer the following:
a. Draw the electron-dot structure of Methane.
b. Define Homologous series.
c. Write the IUPAC names of the following:
1. CH₃ – CH₂ – COOH
2. CH₃ – CHOH – CH₃
3. CH₃ – CO – CH₂ – CH₃
Answer:
i. a. Magnetic effect of electric current is shown in the given figure. [1 Mark]
b. if the number of electric cells is increased on the magnetic needle, the deflection of the needle increases. [1 Mark]
c. If the distance between the conductor and magnetic needle is increased, then the intensity of magnetic field decreases. [1 Mark]
d. 1. If the current is flowing from A to B i.e., south to north, the south pole of the compass needle moves away from point A i.e., towards east. If the current is flowing from B to A i.e., north to south, the south pole of the compass needle moves towards point A i.e., towards west.
2. When a magnetic needle is held near a conductor through which current moves from south to north direction then the south pole of the magnetic needle deflects towards east and if current flows from north to south, the south pole of needle deflects towards west.
e. Ammeter, microphone, electric bell, galvanometer, loud speaker, electric generator, electric motor, telephone receiver, radio, stereo speaker.

ii. a. The electron-dot structure of methane is,

b. The series of carbon compounds formed by joining the same functional group in the place of a particular hydrogen atom on the carbon chains having sequentially increasing length is called homologous series.
c. 1. Propanoic acid
2. Propan-2-ol
3. Butanone

SSC Maharashtra Board Science 1 Question Paper with Solutions