CBSE Class 10 Science paper was conducted on 13 March, 2019. Here, we are providing the detailed and appropriate answers to all the questions asked in the Class 10 Science Question Paper 2019. All the solutions have been explained as per the CBSE marking scheme that is followed while evaluating the answer sheets. Students will find it easy to understand the concepts used in the solutions.
Check the CBSE Class 10 Science Paper Solution 2019 below:
SECTION - A
1. If you could use any source of energy for heating your food which one would you prefer? State one reason for your choice.
Natural gas can be used for heating food because it is a clean source of energy that does not cause any environmental pollution.
2. Write the function of voltmeter in an electric circuit.
A voltmeter is used for measuring the potential difference between two points in an electronic circuit.
SECTION - B
3. What happens to the image distance in the normal human eye when we decrease the distance of an object, say 10 m to 1 m? Justify your answer.
The image distance remains the same due to eye’s ability of accommodation the focal length of eye lens is adjusted. In order to see the nearer object the ciliary muscles contract due to which lens becomes thick and focal length is decreased to obtain a clear image at retina.
4. List two different functions performed by pancreas in our body.
Pancreas performs following two main functions in our body:
(i) Exocrine function: It works as an exocrine gland and helps in the digestion of food. It produces various enzymes such as amylase, lipase and trypsin which help to breakdown carbohydrate, fats and proteins respectively.
(ii) Endocrine function: While working as an endocrine gland it secrets two major hormones, insulin and glucagon which regulate the level of sugar present in the blood.
5. How it can be proved that the basic structure of the Modem Periodic Table is based on the electronic configuration of atoms of different elements?
In Modern’s periodic table we observe the periodicity in properties of the elements in which elements with the similar properties repeat after certain regular intervals when arranged in increasing order of their atomic numbers. The cause of periodicity in properties is the repetition of similar outer electronic configuration after certain regular intervals. This distinct feature of periodicity in properties of the elements is enough to show that the Modem Periodic Table is based on the electronic configuration of atoms of different elements.
5. The electronic configuration of an element is 2, 8, 4. State its :
(a) group and period in the Modern Periodic Table.
(b) name and write its one physical property.
Since the electronic configuration of given element is 2, 8, 4, it’s atomic number is 14 with having 4 valence electrons. Therefore,
(a) It belongs to third period and fourth group of the Modern Periodic Table.
(b) Name of this element is silicon (Si).
Physical properties of silicon: (Any one)
It is solid at room temperature.
It is a non-metal.
It has a very high melting point.
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