Class X SCIENCE PWT-1 QUESTION PAPER

CHEMISTRY -13 MARKS

1. The chemical reaction between Hydrogen sulphide and iodine to give Hydrogen iodide and Sulphur is given below:            H₂S + I₂ → 2HI + S                                 

The reducing and oxidizing agents involved in this redox reaction are:                         1

A) Iodine and Sulphur, respectively 

B) Hydrogen Sulphide and Iodine respectively 

C)Sulphur and iodine, respectively 

D)Hydrogen sulphide and Sulphur, respectively                 

2.What type of reaction is an exothermic reaction?              1

a) Decomposition reaction  

b) Displacement reactions  

c) Combustion reaction  

d) Redox reaction 

3. One of the following does not happen during a chemical reaction. This is:   1

(a) Breaking of old chemical bonds and formation of new chemical bonds. 

(b) Formation of new substances with entirely different properties. 

(c) Atoms of one element change into those of another element to form new products. 

(d) A rearrangement of atoms takes place to form new products. 

4. An acid which can decolorize purple colored potassium permanganate solution is:        1

(a) sulphuric acid                                      

(b) citric acid 

(c) carbonic acid                                       

(d) hydrochloric acid 

5. Assertion (A): Fe₂O₃ + 2Al ------> Al₂O₃ + 2Fe 

The above chemical equation is an example of a displacement reaction.                      1

Reason (R): IRON is more reactive than ALUMINIUM, Produces IRON metal from its oxide. 

a) Both A and R are true and R is the correct explanation of A. 

b) Both A and R are true but R is not the correct explanation of A. 

c) A is true but R is false. 

d) A is false but R is true  

6.  A) Why is silver chloride stored in dark bottles?                                                 2

B) What happens when blue colored crystals of copper sulphate are heated? 

7.What is a chemical equation? Describe one activity each to show that a chemical change has occurred in which (i) change of color ,and (ii) change in temperature has taken place                      2

8. A solution of a substance 'X' is used for testing carbon dioxide. Identify 'X'. What will be its reaction with carbon dioxide? Write a balanced equation for the reaction        2

9. When lead nitrate is heated strongly in a boiling tube, two gases are liberated (with brown fumes), and a yellow solid residue is left behind in the test tube:                   (3)

I) Name the type of chemical reaction and define it. 

II) Write the name and formula of the colored gas liberated. 

III) Write the balanced chemical equation for the reaction.  

Biology (13 marks)

Section A: Multiple Choice Questions (MCQs) (1 mark each)

    1.     Which of the following is not a function of chlorophyll in the process of photosynthesis?

     a)     Absorbing sunlight

 b)    Splitting water molecules

c)     Forming glucose

d)    Increasing the temperature of the leaf

     2.     In human beings, where does the process of digestion of starch begin?  

      a)     Stomach

      b)    Mouth

      c)     Small intestine

      d)    Large intestine

    3.     What is the role of the enzyme pepsin in the stomach?

     a)     It digests proteins

     b)    It digests fats

     c)     It digests carbohydrates

     d)    It emulsifies fats

     Section B: Assertion and Reasoning (1 mark each)

For question numbers 5, 6 two statements are given- one is Assertion (A)and the other

is Reason (R). Select the correct answer to these questions from the options A, B, C, D as given

below: -

A Both Assertion and Reason are true and Reason is the correct explanation of Assertion.

B Both Assertion and Reason are true, but Reason is not the correct explanation of Assertion

C Assertion is true, but Reason is false

D Assertion is false, but Reason is true.

4.     Assertion (A): The process of nutrition in plants is called photosynthesis.

Reason (R): Plants take in carbon dioxide from the air and water from the soil to make their food in the form of glucose.

5.     Assertion (A): The human stomach has a highly acidic environment.

Reason (R): The acidic environment helps in killing harmful bacteria and activates pepsin for protein digestion.

Section C: Case Study-based Question (4 marks)

Case Study:

Rhea is a student who is learning about human nutrition. During a class, her teacher explained how the digestive system breaks down food and absorbs nutrients. Rhea learned that the mouth, stomach, and small intestine play key roles in digestion. She also discovered that enzymes like amylase, lipase, and pepsin help break down complex substances into simpler ones.

1.     Based on this case, answer the following questions:

      a)     What is the role of amylase in the digestive process?

      b)    Why is it important for the small intestine to have a large surface area?

      c)     What happens in the stomach during digestion?

      d)    How does the absorption of nutrients take place in the small intestine?

      Section D: Long Answer Questions (2 marks each)

      2.     Explain the process of protein digestion in human beings.

      3.     What is dark reaction?

Physics (13 marks)

Section A – 1 Mark Each (3× 1 = 3 )

Q1. Define the radius of curvature of a spherical mirror.

Q2. What is the nature of the image formed by a concave mirror when the object is placed at infinity?

Q3. Write the relationship between focal length and radius of curvature of a spherical mirror.

 

Section B – 2 Marks Each (3 × 2 = 6 Marks)

Q5. Draw a ray diagram to show image formation by a concave mirror when the object is placed at the focus.

Q6. List two uses of concave mirrors based on their image-forming properties.

Q7. An object is placed 20 cm in front of a concave mirror of focal length 10 cm. Find the position of the image using the mirror formula. (Give proper signs)

 

Section C – Case Study Based Question (1 × 4 = 4 Marks)

Read the following case and answer the questions:

Rita was getting ready for a function. She stood close to her makeup mirror and observed a large, erect image of her face. Curious, she slowly moved away from the mirror and noticed that the image became inverted and smaller. Her brother explained that the mirror behaves differently depending on how close or far the object is.

Q8.1 What type of mirror is used in the makeup mirror?

Q8.2 What is the nature of the image formed when Rita is very close to the mirror?

Q8.3 What happens to the image when Rita moves beyond the center of curvature?

Q8.4 Why is this type of mirror suitable for use as a makeup mirror?