Students can access the CBSE Sample Papers for Class 10 Science with Solutions and marking scheme Term 2 Set 7 will help students in understanding the difficulty level of the exam.
CBSE Sample Papers for Class 10 Science Term 2 Set 7 for Practice
Time: 2 hours
Maximum Marks: 40
General Instructions:
- All questions are compulsory.
- The question paper has three sections and 15 questions.
- Section-A has 7 questions of 2 marks each; Section-B has 6 questions of 3 marks each; and Section-C has 2 case based questions of 4 marks each.
- Internal choices have been provided in some questions. A student has to attempt only one of the alternatives in such questions.
Section – A
Question 1.
Methane is a one-carbon compound in which the carbon is attached by single bonds to four hydrogen atoms. It is a colourless, odourless, non-toxic but flammable gas (b.p. -161 °C). Study the electron dot structure of methane. [2]
(a) Name the type of bonds formed in this compound.
(b) Why are such compounds poor conductors of electricity?
Question 2.
An element “X” has atomic number 13. The atomic number or proton number (symbol Z) of a chemical element is the number of protons found in the nucleus of every atom of that element. In an uncharged atom, the atomic number is also equal to the number of electrons. [2]
(a) What is the group and period number to which this element “X” belongs?
(b) Is this element “X” a metal or a non-metal? Justify your answer.
Question 3.
Fertilization and implantation are the most critical events in the reproduction process. In this process,
both egg and sperm are fused together to form a zygote. Later, it gets implanted into the uterus and the development of an organism starts. The given flowchart explains the process. Study the chart and answer the questions given below: [2] (HI
(a) Identify the labels X, Y and Z.
(b) Where does the process of fertilisation takes place in female body?
Question 4.
In biology class, a teacher shows here students, the process of germination of pollen on stigma. Also, she told that the germination of pollen grain in stigma occurs in ‘in vivo’ conditions. It is called as fertilisation. Pollen grains are the male gametes and stigma is the female floral part. Ovule contains the egg cell. Based on the information and diagram given below, answer the questions given below: [2]
(a) Identify ‘A’ and explain how it reaches part ‘B’.
(b) What happens to the part marked ‘D’ after fertilisation is over?
Question 5.
In a cross between plants with purple flowers and plants with white flowers, the F^ had all white flowers. When F1 generation was self bred, the F2 generation gave rise to 100 individuals, 75 of which had white flowers. Make a cross and find the genotypes of F2 individual? What is the ratio of purple and white flowered plants in F2 generation? [2]
OR
Chromosomes are long thread-like structures which contain hereditary information of the individual and are thereby the carriers of genes and hereditary characteristics. [2]
Explain how in sexually reproducing organisms the number of chromosomes in the progeny is maintained?
Question 6.
A compass consists of a small metal needle which is magnetised itself and which is free to turn in any direction. Therefore in the presence of a magnetic field, the needle is able to line up in the same direction as the field. Shivani placed a magnetic compass needle in the plane of paper near point A as shown in the figure.
(a) In which plane should a straight current carrying conductor be placed so that it passes through point A and there is no change in the deflection of the compass?
(b) Under what condition is the deflection maximum and why? [2]
OR
(a) What is magnetic effect of current?
(b) How can you determine the polarity of a current carrying circular loop just by watching the direction of current? [2]
Question 7.
Rahul was studying a terrestrial food chain. He observed the flow of energy as follows:
(a) If autotrophs occupying the first trophic level are called producers, what are herbivores called as ?
(b) How much energy does the lion get in the above food chain ?
OR
The diagram shows the flow of energy through an ecosystem. [2]
The smallest amount of energy transferred between organisms and the largest amount of energy lost to the ecosystem is represented by which arrows?
Section – B
Question 8.
Valency is the combining capacity of an element. The electrons present in the outermost shell of an atom are known as ‘Valence electrons’. Based on the group valency of elements, write the molecular formula of the following compounds giving justification for each: [3]
(a) Oxide of first group elements.
(b) Halide of the elements of group thirteen, and
(c) Compound formed when an element A of group 2 combines with an element B of group 17.
Question 9.
Explain the following: [3]
(a) CH3COOH is a weak acid.
(b) Propene undergoes addition reaction.
(c) The gas stoves have inlets for air.
OR
(a) Which compounds are called
(i) alkanes,
(ii) alkenes and
(iii) alkynes? C4H10 belongs to which of these?
(b) Draw two structural isomers of this compound. [3]
Question 10.
Study the given cross showing self pollination in F1.
Fill in the blank and answer the questions that follows: [3]
(a) In the above question, what is the combination of characters in the F2 progeny? What are the ratios?
(b) What does the result in F1 generation, signifies?
Question 11.
B1, B2 and are three identical bulbs connected as shown in the figure. When all the three bulbs glow, [3]
(a) What happens to the glow of the other two bulbs when the bulb B1 gets fused?
(b) What happens to the reading of A1, A2, A3 and A when the bulb B2 gets fused?
Question 12.
Calculate the equivalent resistance and potential difference between the points A and B is the circuit where 2A is the circuit current as shown below: [3]
(a) Identify “the layer P”. How it is produced?
(b) Name the synthetic chemicals mainly responsible for its drop in the atmosphere. How can the use of these chemicals be reduced?
Section – C
This section has 02 case-based questions (14 and 15). Each case is followed by 03 sub-questions (a), (b) and (c). Parts (a) and (b) are compulsory. However, an internal choice has been provided in part (c).
Question 13.
Layer P shields the surface of the earth from the UV radiation. It is found in the stratosphere around 15 – 30 km above the, earth’s surface. It protects the life on earth by absorbing harmful ultraviolet-B (UV-B) radiation from the sun. [3]
(a) Identify the layer P”. How it is produced?
(b) Name the synthetic chemicals mainly responsible for its drop in the atmosphere. How can the use of these chemicals be reduced?
Question 14.
In a pea plant, the phenotypes like round seed and yellow colour are completely dominant over the other i.e., green wrinkled seeds. Sanjana decides to pollinate one flower of a plant with yellow round and green wrinkled seeds and obtained the following result. Based on the schematic diagram, answer the following questions.
(a) Write the phenotypes of F1 progeny. [1]
(b) Name the phenotypes produced in F2 progeny upon self-pollination of F1 progeny. [1]
(c) Identify 1,4,5 and 6 in the diagram. [2]
OR
List any two contrasting characters other than roundness of pea seeds that Mendel used in his experiments with pea plants. [2]
Question 15.
A student fixes a sheet of white paper on a drawing board. He places a bar magnet in the centre of it. He sprinkles some iron filings uniformly around the bar magnet. Then he taps the board gently and observes that the iron filings arrange themselves in a particular pattern. [4]
(a) Why do the iron filings arrange in a pattern? [1]
(b) What do the lines along which the iron filings align represent? [1]
(c) What does the crowding of iron filings at the end of the magnet indicate? How the strength of magnetic field is indicated? [2]
OR
If the magnet is placed in the same position after rotating 1800, what will be the changes in the magnetic field lines? Explain with reason. (2)