Maharashtra Board SSC Class 10 Science 1 Sample Paper Set 7 with Answers Solutions Pdf Download.
Maharashtra Board Class 10 Science 1 Model Paper Set 7 with Answers
Time: 2 Hours
Total Marks: 40
Note:
- All questions are compulsory.
- Use of a calculator is not allowed.
- The numbers to the right of the questions indicate full marks.
- In case of MCQs (Q. No. 1(A)) only the first attempt will be evaluated and will be given credit.
- 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) - Scientifically correct, labelled diagrams should be drawn wherever necessary.
Question 1.
(A) Choose the correct alternative. [5]
i. For two balls of equal masses as shown in the figure, the magnitude of gravitational force between them is F. (C)
In which of the conditions shown in the options below, the gravitational force remains same i.e., F?
Answer:
C
ii. A _________ lens always produce virtual and diminished image. (B)
(A) biconvex
(B) biconcave
(C) planoconvex
(D) bifocal
Answer:
(B) biconcave
iii. In _________ appliance, Fleming’s left hand rule is not used. (C)
(A) electric fan
(B) mixer
(C) computer
(D) electric generator
Answer:
(C) computer
iv. When a light ray makes an angle of 90° while entering a glass slab from air, it _________. (C)
(A) bends towards the normal.
(B) goes away from the normal.
(C) goes straight without bending at glass-air interface.
(D) returns back into the air.
Answer:
(C) goes straight without bending at glass-air interface.
v. Which gas is liberated when aluminium metal reacts with dilute hydrochloric acid? (B)
(A) Oxygen
(B) Hydrogen
(C) Chlorine
(D) Hydrogen peroxide
Answer:
(B) Hydrogen
(B) Answer the following. [5]
i. Identify the terms A and B in the given diagram.
ii. Find the odd one out and write explanation.
Sodium, Potassium, Calcium, Iron
iii. State true or false. Rewrite the correct statement if false.
An illusion of the appearance of water on a hot road or in a desert is an example of dispersion of light.
iv. Match the columns.
| Column I | Column II |
| a. Electric fuse | 1. Magnetic effect of electric current |
| b. Electric fan | 2. Heating effect of electric current |
| 3. Electromagnetic induction |
v. By considering second correlation complete the first correlation:
Gravitational constant (G): _________ :: Acceleration due to gravity : m/s²
Answer:
i. A: High earth orbits; B: Low earth orbits
ii. Iron
Iron is a d-block element while others are s-block elements.
iii. False.
An illusion of the appearance of water on a hot road or in a desert is an example of mirage.
iv.
| Column I | Column II |
| a. Electric fuse | 2. Heating effect of electric current |
| b. Electric fan | 3. Electromagnetic induction |
v. Gravitational constant (G) : Nm²/kg² :: Acceleration due to gravity : m/s²
Question 2.
(A) Give scientific reasons. (Attempt any 2) [4]
i. Geostationary satellites are not useful for studies of polar regions.
ii. Elements belonging to the same group have the same valency.
iii. We cannot clearly see an object kept at a distance less than 25 cm from the eye.
(B) Answer the following. (Attempt any 3) [6]
i. Give four examples of natural macromolecules.
ii. Complete the following table for the space missions undertaken by ISRO.
iii. Define endothermic reaction. Give an example.
iv. How much heat energy is necessary to raise the temperature of 10 kg of water from 40 °C to 100 °C?
v. If the speed of light in a medium is 2 x 10s m/s, what is the absolute refractive index of the medium? (Velocity of light in vacuum = 3 x 108 m/s)
Answer:
(A) i. a. Satellites revolving around the earth with the time period same as that of rotation of earth are called geostationary satellites.
b. These satellites revolve in orbits parallel to the equator of the earth at height of around 35780 km from the surface of the earth.
c. As, the orbits of such satellites are always above the equator, these satellites are not useful for studies of polar region.
ii. a. The electronic configuration of the outermost shell is same for all the elements belonging to the same group.
b. So, the number of valence electrons for all the elements in a group is the same.
c. The valency of an element is determined by the valence electrons.
Hence, elements belonging to the same group have the same valency.
iii. a. The muscles attached to the eye lens (ciliary muscles) help in fine adjustments of the focal length of the lens.
b. The capacity of these muscles to contract or relax to adjust the focal length (i.e., power of accommodation) has a limit.
c. The minimum distance of an object from a normal eye for which the eye lens can decrease its focal length to the least possible value, is 25 cm.
Hence, we cannot clearly see an object kept at a distance less than 25 cm from the eye.
(B) i. Examples of natural macromolecules:
a. Starch
b. Cellulose
c. Rubber
d. Silk
ii.
iii. a. The chemical reactions which are accompanied by absorption of heat are called endothermic reactions.
b. Example: When calcium carbonate (CaCO3) is strongly heated, it undergoes decomposition to form calcium oxide (CaO) and carbon dioxide (CO2).
iv. Solution:
Given:Mass (m) = 10 kg, specific heat of water (c) = 1 kcal/kg °C
Change in temperature (∆T) = 100 – 40 = 60 °C
To find: Heat energy (Q)
Formula: Q = m c ∆T
Calculation: According to principle of heat exchange,
Energy supplied to water = Energy gained by water From formula,
Q = 10 × 1 × 60 = 600 kcal
Ans: Heat energy necessary to raise temperature of water is 600 kcal.
v. Solution:
Given:
Speed of light in medium (v2) = 2 × 108 m/s, velocity of light in vacuum (v1) = 3 × 108 m/s
To find: Absolute refractive index (n)
Formula: n = \(\frac{v_1}{v_2}\)
Calculation: From formula,
n = \(\frac{3\times10^8}{2\times10^8}\) = 1.5
Ans: The absolute refractive index of the medium is 1.5.
Question 3.
Answer the following. (Attempt any 5) [15]
i. The orbit of a planet is an ellipse with the Sun at one of its foci. The Sun’s position is indicated as ‘O’. X1Y1 and X2Y2 are the distances covered by the planet in equal time. X1O and X2O lines sweep equal area in equal intervals of time. Hence, areas X1OY1 and X2OY2 are equal. Also, the time taken by the planet to complete one revolution around the Sun depends on its mean distance (r) from the Sun.
a. Which laws do we understand from the description given above?
b. If shaded area X3OY3 is n times the area from X1OY1 then what will be the relation between time taken by the planet to move X1 to Y1, say t1 and time taken by the planet to move from X3 to Y3, say t2?
c. State the law explained in the description which is used to formulate inverse square law of gravity.
ii. Complete the following table:
iii. State and explain Newlands’ law of octaves.
iv. Study the diagram and answer the questions given below.
a. Name the optical instrument shown in the diagram.
b. Label the diagram correctly.
c. Write the working of this instrument.
v. Select appropriate options and complete the following paragraph:
(ores, gangue, metallurgy, electrolysis, minerals, gold, iron, platinum)
Based on their reactivity, most of the metals are found in combined state in the earth’s crust while some metals such as silver, _________ and _________ are found in free state. The compounds of metals which occur naturally in the earth’s crust are known as _________. The minerals from which metals can be profitably extracted are called _________. Ores mined from earth usually contain large amount of impurities like sand, soil, etc. These impurities are called _________. The extraction of metals from their ores and then refining them for use is known as _________.
vi. Calculate the refractive index of water with respect to glass and refractive index of glass with respect to water, if speed of light in water and glass is 2.2 × 108 m/s and 2 × 108 m/s respectively.
vii. Label the diagram given below and explain it.
viii. Explain the role of latent heat in the change of state of a substance.
Answer:
i. a. Kepler’s laws of planetary motion are understood from the given description.
b. As area X3OY3 = n x area X1Oy1, the time taken to go from X3 to y3 is n times the time taken to go from X1 to y1.
∴ t2 = nt1
SMART TIP
Note that according to Kepler’s second law, equal areas are swept in equal time intervals.
c. Kepler’s third law of planetary motion is used to formulate inverse square law of gravity. It states that, the square of orbital period of revolution of a planet around the Sun is directly proportional to the cube of the mean distance of the planet from the Sun.
ii.
SMART TIP
In decomposition reaction, the number of products is more than reactant. In displacement reaction, only one ion changes its place whereas in double displacement reaction, two ions exchange their places.
iii. Statement: “When the elements are arranged in an increasing order of their atomic masses, the properties of the eighth element are similar to the first.”
Explanation:
a. Newlands correlated the atomic masses of elements to their properties in a different way.
b. He arranged the elements known at that time in an increasing order of their atomic masses.
c. This arrangement started with the lightest element hydrogen and ended up with thorium.
d. He found that every eighth element had properties similar to those of the first element as observed in octaves of music.
Example: Sodium is the eighth element from lithium and both have similar properties.
iv. a. Optical instrument shown in the figure is compound microscope
b. Labelled diagram:
c. Working: Magnification in compound microscope is obtained by the combined effect of two lenses. The magnification occurs in two stages. The image formed by the first lens acts as the object for the second lens. Clear image can be obtained by adjusting the distance between two lenses.
v. Based on their reactivity, most of the metals are found in combined state in the earth’s crust while some metals such as silver, gold and platinum are found in free state. The compounds of metals which occur naturally in the earth’s crust are known as minerals. The minerals from which metals can be profitably extracted are called ores. Ores mined from earth usually contain large amount of impurities like sand, soil, etc. These impurities are called gangue. The extraction of metals from their ores and then refining them for use is known as metallurgy.
vi. Solution:
Given: Speed of light in water (vw) = 2.2 × 108 m/s,
speed of light in glass (vg) = 2 × 108 m/s
a. Refractive index of glass w.r.t. water (wng)
b. Refractive index of water w.r.t glass (gnw)
Ans: a. Refractive index of glass w.r.t. water is 1.1.
b. Refractive index of water w.r.t glass is 0.909.
vii. Labelled diagram:
a. Wilfley’s table is made by fixing narrow, thin and long wooden riffles on an inclined surface.
b. The table is given a regular vibrating motion.
c. The powdered ore obtained from lumps of the ore using ball mill is fed on the top of Wilfley’s table and running stream of water is also released from the upper side.
d. As a result, the lighter gangue particles are carried away by water and heavy ore particles in which proportion of minerals is more, settle between the wooden riffles fixed on the table and get collected on the slits between them.
viii. a. The heat energy required to change substance from one state to another at constant temperature is called as latent heat of substance.
b. When latent heat is supplied to a substance, it is utilised for weakening the bonds between atoms or molecules of the substance.
c. When solid substance is provided with latent heat of fusion, weakening of bonds results into distancing of atoms or molecules of solids and eventually it changes into liquid state.
d. Similarly, when liquid substance is provided with latent heat of vaporisation, it changes into gaseous state.
e. Conversely when latent heat is released or given off from a substance, it results into strengthening the bonds between atoms or molecules causing change of state of the substance.
f. When a liquid substance gives off latent heat of fusion, bonds between atoms or molecules grow stronger bringing them closer and eventually liquid changes into solid.
g. Similarly, when a gaseous substance gives off latent heat of vaporisation, it changes into liquid.
Question 4.
Answer the following. (Attempt any 1) [5]
i. When ethanol is heated at 170 °C with cone. H2S04, it forms an organic compound ‘A’ and water. The compound ‘A’ reacts with hydrogen in the presence of nickel to form ‘B’.
a. Name the compound A and write its chemical formula.
b. Name the compound B and write its chemical formula.
c. Write the chemical equation of the reaction involved in formation of ‘B’ from ‘A’.
d. Identify the homologous series to which A and B belongs.
e. ‘B’ undergoes combustion in presence of sufficient amount of oxygen to release large amount of heat and light. Write its chemical equation.
ii. Explain the construction and working of an electric motor. Draw a neat diagram and label it.
Answer:
i. a. Compound A is ethene (CH2 = CH2).
b. Compound B is ethane (CH3 – CH3).
c. Reaction:
d. Compound A (ethene) belongs to the homologous series of alkenes.
Compound B (ethane) belongs to the homologous series of alkanes.
e. When compound B (ethane) undergoes combustion in sufficient supply of oxygen, it forms carbon dioxide (CO2) and water (H2O) along with the release of large amount of heat and light.
SMART TIP
In combustion of carbon compounds, the products are CO2 and H2O.
ii. Electric motor:
It is a device which converts electrical energy into mechanical energy.
Construction: Electric motor consists of following parts:
a. Rectangular coil: A large number of turns of insulated copper wire wound on iron core in rectangular shape forms a coil ABCD as shown in figure.
b. Strong magnet: The coil is placed in between two pole pieces (N and S) of a strong horse shoe magnet which provides a strong magnetic field. The sides AB and CD are perpendicular to the direction of magnetic field.
c. Split ring: It consists of two halves of a metallic ring (R1 and R2). The ends of the coil are connected to these rings.
The outer conducting surfaces of spilt rings R1 and R2 are in contact with the two stationary carbon brushes. Spilt rings reverse the direction of current in the coil.
d. Brushes: Two carbon brushes B1 and B2 are used to press the split rings.
e. Axle: The two halves of the rings have resistive coating in their inner surfaces and are tightly fitted on the axle. The main function of axle is to rotate with the coil.
f. Battery: The battery supplies the current to the coil.
Working:
a. When the circuit is completed, the current passes through the brush B1 from A to B in branch AB.
b. As, the magnetic field acts from north pole to south pole, according to Fleming’s left hand rule, the force experienced by arm AB is in the downward direction and arm CD is in the upward direction.
c. Both these forces are equal in magnitude and opposite in direction and hence, the coil rotates in anticlockwise direction.
d. After half rotation, the split rings R2 and R1 come in contact with brushes B1 and B2 respectively.
e. Again the current starts passing through the coil in opposite direction.
f. The force acting on branch BA is upward and DC is downward, this force again moves the coil in anticlockwise direction.
g. This shows that the current in the loop A BCD is reversed after every half rotation, and the loop continues to rotate in same direction.
h. Thus, the coil rotates with the help of electrical energy.