As per 2019 CBSE Question Paper Design
Class: 10th Class CBSE
Time Allowed: 3 Hours
Maximum Marks: 80
- The question paper comprises five sections: A, B, C, D and E. You are to attempt both the sections.
- All questions are compulsory.
- Internal choice is given in sections B, C, E and E.
- Question numbers 1 and 2 in sections A are one marks questions. They are to be answered in one words or in one sentence.
- Question numbers 3 to 5 in sections B are two marks questions. These are to be answered in 30 words each.
- Question numbers 6 to 15 in sections C are three marks questions. These are to be answered in about 50 words each.
- Question numbers 16 to 21 in sections D are five marks questions. These are to be answered in 70 words each.
- Question numbers 22 to 27 in sections E are based on practical skills. Each questions is a two marks question. These are to be answered in brief.
10 Science Solved Sample Paper 5 – Page 1
Question: 1. Name the component of a solar cooker that produces a green house effect inside it. 
Answer: Glass sheet
Question: 2. Out of C2H6 and C2H4, identify the saturated compound. Give reason in support of your answer. 
Question: 3. When a concave mirror is placed facing the sun, the sun’s rays converge to a point 10 cm from the mirror. Now, an erect, 2 cm-long pin is placed 20 cm away on the principal axis of the mirror. If you want to get the image of the pin on a card, where would you place the card? What would be the nature of the image? 
Answer: f = – 10 cm, u = – 20 cm
As we know, 1/v = 1/f – 1/u = 1/-10 – -1/20 ⇒ v = -20 cm
Object is placed at C, therefore image is also at C. Nature → Real, inverted and same size.
An object of height 1.2 cm is placed before a concave mirror of focal length 20 cm so that a real image is formed at a distance of 60 cm from it. Find the position of an object. What will be the height of the image formed?
Question: 4. In the context of conservation of natural resources, explain the tern ‘reduce’. From among the materials that we use in daily life, identify any two materials for this category. 
Reduce: Use materials in lesser quantity.
Example: electricity, water or any other.
Question: 5. Effervescence are formed when the batter for cake is heated. Which substance is added to the batter to make the cake soft and fluffy and name the gas evolved. Write chemical equation involved. 
Answer: The substance present in the batter is baking soda. (NaHCO2). The gas evolved is CO2.
2NaHCO2 + H → Sodium salt of acid + H2O + CO2