Class 10 Science – Sample Question Paper

Chapter: Metals and Non-Metals
Set: B
Time: 1 Hour
Maximum Marks: 35

---

Section A – Objective Type (1 mark each)

1. Which non-metal is used in making fertilisers?

2. Name one soft metal that can be cut with a knife.

3. Write the formula of rust.

4. Which metal is the best conductor of electricity?

5. Which non-metal exists in the form of a diamond?

6. Name the metal that does not react with dilute HCl.

Section B – Very Short Answer (2 marks each)

7. What is corrosion? Write one method to prevent it.

8. Why are metals electropositive in nature?

9. Write a balanced chemical equation for the reaction between iron and copper sulphate solution.

10. How does sulphur differ from metals in terms of physical properties?

11. Define displacement reaction. Give an example using a metal.

Section C – Short Answer (3 marks each)

12. (a) What happens when a small piece of sodium is dropped in water? (b) Write the balanced chemical equation. (c) Name the gas evolved.

13. (a) What is meant by the refining of metals? (b) Name and explain the method used for refining copper.

14. (a) Give two chemical properties of non-metals. (b) Why do non-metals form acidic oxides? (c) Write one reaction to show this.

Section D – Long Answer (4 marks each)

15. (a) Explain the steps involved in the extraction of metal from its sulphide ore. (b) Why is it necessary to convert sulphide into oxide before reduction?

16. (a) List four differences between metals and non-metals. (b) Write one example for each difference.

ACID BASE AND SALT

 

Class 10 Science – Practice Question Paper

Chapter: Acids, Bases, and Salts
Time: 1 Hour
Maximum Marks: 40

Section A: (1 Mark Each) – Very Short Answer 

1. What is the chemical name and formula of baking soda?

2. Name a strong acid and a strong base.

3. What is the colour of methyl orange in acidic solution?

4. Which acid is present in tamarind?

5. What is the pH range of basic substances?

---

 Section B: (2 Marks Each) – Short Answer Type I 

6. Define acids and bases as per the Arrhenius theory.

7. What happens when an acid reacts with a metal? Give a balanced chemical equation.

8. Why does an aqueous solution of an acid conduct electricity?

9. Give one use each of:
   a) Plaster of Paris
   b) Bleaching powder

10. Why is common salt important for our body?

11. What is the effect of acids and bases on litmus paper?

Section C: (3 Marks Each) – Short Answer Type II 

12. Write the chemical equations for the following:
    a) Sodium hydroxide reacts with hydrochloric acid
    b) Zinc reacts with sulphuric acid
    c) Calcium carbonate reacts with hydrochloric acid

13. Explain the preparation of washing soda from baking soda.

14. What is the neutralization reaction? Give two examples from everyday life.

15. Differentiate between strong and weak acids with two examples each.

16. Why does acid rain occur? Mention one harmful effect of it.

Section D: (5 Marks Each) – Long Answer 

a) Explain the importance of pH in everyday life (at least 3 examples).
b) A sample of rainwater has a pH of 5.6. Is it acidic or basic? Why?

a) Describe a neutralization reaction with a labelled diagram.
b) How is the pH of soil tested, and why is it important in agriculture?

a) What is bleaching powder? How is it prepared?
b) Mention two uses of it.
c) How does it help in water purification?

Rational Numbers

Class 7 – Mathematics

Practice Paper: Rational Numbers

Chapter: Rational Numbers
Time: 1 Hour | Marks: 30

---

Section A – Multiple Choice Questions (1 mark each)

1. Which of the following is a rational number?
   a) √2
   b) π
   c) 3/7
   d) 5.324324...

2. The additive inverse of $\frac{-5}{8}$ is:
   a) $\frac{5}{8}$
   b) $-\frac{5}{8}$
   c) 0
   d) $\frac{8}{5}$

3. Which rational number lies between $\frac{-3}{4}$ and $\frac{1}{2}$?
   a) $\frac{5}{6}$
   b) $-1$
   c) $-\frac{1}{2}$
   d) $\frac{3}{4}$

---

Section B – Very Short Answer Questions (2 marks each)

4. Write two rational numbers equivalent to $\frac{-3}{5}$.

5. Represent $\frac{-2}{3}$ on a number line.

---

Section C – Short Answer Questions (3 marks each)

6. Find the value of:

   $$\frac{3}{4} + \left( -\frac{5}{6} \right)$$
   

7. Arrange the following rational numbers in ascending order:
   $\frac{-1}{2}, \frac{3}{4}, \frac{-2}{3}$

8. Simplify:

   $$\left( \frac{4}{9} \div \frac{-2}{3} \right) \times \left( \frac{-3}{5} \right)$$
   

---

Section D – Long Answer Questions (4 marks each)

9. Verify the associative property of addition for the rational numbers:
   $\frac{1}{2}, \frac{-3}{4}, \frac{5}{6}$

10. A number when added to $\frac{-3}{7}$ gives $\frac{2}{3}$. Find the number.

 

Chapter: Rational Numbers – Practice Question Paper

Time: 1 Hour
Maximum Marks: 30

---

Section A: Very Short Answer Questions (1 mark each)

(Answer in one line)

1. Define a rational number.

2. What is the additive identity of rational numbers?

3. Write two rational numbers between 1/2 and 3/4.

4. Express 0.25 as a rational number in p/q form.

5. Is 0 a rational number? Why or why not?

---

Section B: Short Answer Questions (2 marks each)

6. Simplify:

   $$\frac{3}{5} + \frac{2}{7}$$

7. Find the multiplicative inverse of:
   a) $\frac{-4}{9}$
   b) $\frac{7}{-3}$

8. Arrange the following rational numbers in ascending order:

   $$\frac{1}{3}, -\frac{2}{5}, \frac{4}{9}, 0$$
   

9. Subtract:

   $$\left(\frac{-3}{8}\right) - \left(\frac{5}{12}\right)$$
   

---

Section C: Long Answer Questions (3 marks each)

10. Verify:

$$\left(\frac{2}{3} + \frac{4}{5}\right) + \frac{1}{2} = \frac{2}{3} + \left(\frac{4}{5} + \frac{1}{2}\right)$$

(Associativity of addition)

11. A man had ₹1200. He gave $\frac{1}{4}$ of the amount to his friend, and $\frac{2}{5}$ to his sister. How much money is he left with?

12. If $a = \frac{2}{7}$, $b = \frac{3}{4}$, and $c = \frac{-5}{6}$, verify that:

$$a \times (b + c) = a \times b + a \times c$$\

---

Section D: Word Problem (4 marks)

13. The temperature of a place in the morning was $-2^\circ \text{C}$ It rose by ${\frac{5}{2}}^{\circ }$ by afternoon and then dropped by ${\frac{7}{4}}^{\circ }$ in the evening.
    What was the temperature in the evening?

Chemical Reactions and Equations

 

Class 10 Science – Practice Question Paper

Chapter: Chemical Reactions and Equations
Maximum Marks: 20
Time: 45 Minutes

Section A (1 mark each)

1. Define a chemical reaction.

2. Write the balanced chemical equation for the reaction between hydrogen gas and oxygen gas to form water.

3. What is meant by a balanced chemical equation? Why should chemical equations be balanced?

4. Name the type of reaction:

   • (i) Burning of magnesium ribbon in air

   • (ii) Rusting of iron

5. What is a precipitation reaction? Give an example with a balanced equation.

Section B (2 marks each)

6. What is the difference between a combination reaction and a decomposition reaction? Give one example for each.

7. Write the balanced chemical equation for the following and identify the type of reaction:

   • (a) Zinc reacts with hydrochloric acid

   • (b) Copper sulfate reacts with iron

8. A solution of lead nitrate is mixed with a solution of potassium iodide. Write the balanced chemical equation for the reaction and state the type of reaction.

Section C (3 marks each)

9. Explain redox reactions with the help of an example.

10. What is corrosion? How does it affect metals? Mention two ways to prevent corrosion.

11. (a) What happens when baking soda (NaHCO₃) is heated? Write the chemical equation.
    (b) What is observed when quicklime is added to water? Write the equation.

Section D (4 marks each)

12. Balance the following chemical equations and mention the type of reaction:

• (a) Na + H₂O → NaOH + H₂

• (b) BaCl₂ + Al₂(SO₄)₃ → BaSO₄ + AlCl₃

• (c) CaCO₃ → CaO + CO₂

• (d) Fe + CuSO₄ → FeSO₄ + Cu

13. Consider the reaction:
    $2KClO₃ → 2KCl + 3O₂$

    • (a) Name the type of reaction.

    • (b) What is the role of heat in this

CLASS 7 Electric Current and Its Effects

 Worksheet 1

Class 7 Science 

Chapter: Electric Current and Its Effects
(CBSE Pattern)

---

Section A: Very Short Answer Questions (1 Mark Each)

1. Define electric current.
2. What is an electric circuit?
3. Name any two appliances that work using the heating effect of electric current.
4. What is an electromagnet?
5. What is the role of a switch in an electric circuit?
6. What happens when an electric current passes through a coil wound around an iron nail?

---

Section B: Short Answer Questions (2 Marks Each)

7. Differentiate between a closed circuit and an open circuit.
8. Explain the heating effect of electric current with an example.
9. What is the function of an electric fuse?
10. Why is tungsten used in the filament of an electric bulb?
11. What is meant by the magnetic effect of electric current?
12. Why does a compass needle deflect when placed near a current-carrying wire?

---

Section C: Long Answer Questions (3 Marks Each)

13. Explain how an electric bell works with the help of a labeled diagram.
14. How is an electromagnet made? Mention two uses of electromagnets.
15. What factors affect the amount of heat produced in a wire when current flows through it?
16. Describe how a fuse prevents electrical hazards.

Worksheet 2

Class 7 Science – Electric Current and Its Effects

Maximum Marks: 25
Time: 1 Hour

---

Section A – Very Short Answer Questions (1 Mark Each)

1. What is an electric circuit?
2. Define an electric fuse.
3. What is the SI unit of electric current?
4. Name one appliance that works due to the heating effect of electric current.
5. Who discovered the magnetic effect of electric current?

---

Section B – Short Answer Questions (2 Marks Each)

6. Explain the heating effect of electric current with an example.
7. Why is tungsten used as the filament in an electric bulb?
8. How does an electric fuse protect electrical appliances?
9. What is an electromagnet? Mention one of its uses.
10. What happens when an electric current flows through a wire?

---

Section C – Long Answer Questions (3 Marks Each)

11. Explain the working of an electric bell with a neat diagram.
12. Describe an experiment to show the magnetic effect of electric current.
13. How does the strength of an electromagnet increase? Mention two factors.
14. List three devices that work on the principle of the heating effect of electric current and explain one of them.

---

Section D – Diagram-Based Question (4 Marks)

15. Draw a labeled diagram of an electric bell and explain its working.

Class 8 Friction

 

1. Define friction.

Ans. Friction is the force that opposes the relative motion between two surfaces in contact.

2. What is force of friction?

Ans. The force of friction is the resistive force acting between two surfaces in contact, which opposes motion.

3. What is the cause of friction? How can it be minimized?

Ans. Friction is caused by the roughness of surfaces and interlocking of irregularities at a microscopic level. 

It can be minimized by lubrication, polishing, using ball bearings, or streamlining objects.

4. Friction is required for walking. Explain.

Ans. Friction provides the necessary grip between our feet and the ground, allowing us to push against it and move forward. Without friction, walking would be difficult.

5. What is rolling friction?

Ans. Rolling friction is the frictional force that resists the motion of an object rolling over a surface. It is much smaller than sliding friction.

6. What is sliding friction?

Ans. Sliding friction is the resistance encountered when one surface slides over another. It is greater than rolling friction.

7. What do you mean by the term drag?

Ans. Drag is the resistive force experienced by an object moving through a fluid (air or water).

8. What is the direction of frictional force?

Ans. Frictional force always acts in the opposite direction to the motion of the object.

9. Give one difference between frictional force and gravitational force.

Ans. Frictional force opposes motion and acts only when objects are in contact, while gravitational force is an attractive force that acts between two masses at a distance.

10. Frictional force is used to stop a moving bicycle. How?

Ans. When brakes are applied, friction between the brake pads and the wheel reduces the wheel’s motion, eventually stopping the bicycle.

11. State the factors on which friction depends.

Ans. Friction depends on the roughness of surfaces in contact and the normal force pressing them together.

12. Why does a ball rolling along the ground stop after some time?

Ans. The ball stops due to rolling friction and air resistance acting against its motion.

13. Why do kabaddi players rub their hands with soil while playing?

Ans. Rubbing hands with soil increases friction, improving grip and reducing slipperiness due to sweat.

14. Give reasons:

(a) Sparks are produced when a pair of scissors is sharpened against a grinding wheel. (b) A piece of chalk wears out as it is used on a blackboard.
Ans. (a) The friction between the scissors and the wheel generates heat and tiny particles that burn as sparks.
(b) Friction between the chalk and the board causes tiny chalk particles to wear off, forming marks on the board.

15. Why are wet surfaces more slippery?

Ans. Water reduces friction by forming a thin layer between surfaces, preventing direct contact and making surfaces slippery.

16. How is the force of friction on a body in a fluid minimized?

Ans. Friction in fluids is minimized by streamlining the shape of objects, reducing surface roughness, and using smooth materials.

17. Why does a hovercraft travel much faster than a steamer pushing through water?

Ans. A hovercraft floats on a cushion of air, reducing contact with water and minimizing friction, while a steamer experiences high water resistance.

18. State the factors on which drag depends.

Ans. Drag depends on the speed of the object, the shape of the object, and the density of the fluid.

19. Give reasons:

(a) Powder is applied to a carrom board.

(b) A man walking on a street slips on a banana skin.

(c) Oil is applied to the moving part of a machine.
Ans. (a)Powder reduces friction, making it easier for the striker and coins to glide.
(b)A banana skin reduces friction, making the surface slippery.
(c)Oil reduces friction, preventing wear and tear and ensuring smooth movement.

20. Friction produces heat. Give one advantage and one disadvantage of this property. 

Ans. Advantage: Helps in lighting a matchstick.
Disadvantage: Causes wear and tear in machine parts.

21. Mention three ways in which friction between two surfaces can be minimized.

Ans. By using lubricants, ball bearings, and polishing surfaces.

22. Mention three examples by which friction between two surfaces can be increased.

Ans. By using rough surfaces, adding treads to shoes, and increasing normal force.

23. State and explain different types of friction. 

Static friction, Sliding friction, Rolling friction, Fluid friction.

Ans. Static friction: Friction that prevents an object from starting to move.
Sliding friction: Friction that resists motion when an object slides over another.
Rolling friction: Friction that occurs when an object rolls over a surface.
Fluid friction: Resistance experienced by objects moving in fluids.

24. Define: 

(a) Fluid friction (b) Streamlining

Ans. (a) Fluid friction: The resistance experienced by an object moving through a fluid (liquid or gas).
(b) Streamlining: The process of designing objects with smooth, curved shapes to reduce fluid friction.

25. What are the advantages of frictional force in our daily life?

Ans. Enables walking, writing, holding objects, driving, and stopping vehicles.

26. Define force of friction. How is the force of friction disadvantageous?Ans. 

The force of friction is the resistive force between two surfaces in contact.
Disadvantages: Causes wear and tear, produces unwanted heat, and reduces efficiency in machines.

27. Mention three disadvantages of friction between the parts of a machine.

Ans. 1, Causes wear and tear – Friction damages machine parts over time, reducing their lifespan.
2. Generates heat – The heat produced by friction can overheat and damage components.
3, Wastes energy – More force is required to overcome friction, reducing machine efficiency

27. Why does a cycle slow down when we apply brakes?

Ans. Friction between brake pads and the wheel reduces motion, slowing down the cycle.

28. Define static and sliding friction. 

Ans. Static friction: The friction that prevents motion when a force is applied.
Sliding friction: The friction acting when an object is already in motion.

29. Why is it easier to move a box that is already in motion than to get it in motion?

Ans. When a box is at rest, static friction acts between the box and the surface. Static friction is stronger because it resists the initial movement by interlocking surface irregularities.
Once the box starts moving, static friction is overcome, and sliding friction takes over. Sliding friction is weaker than static friction, so less force is needed to keep the box in motion.

30. You spill some soapy water on the floor. Would it make it easier or more difficult to walk? Explain.

Ans. It would be more difficult because soap reduces friction, making the floor slippery.

31. Is rolling friction smaller or greater than sliding friction?

Ans. Rolling friction is smaller than sliding friction.

32. Why do sportsmen use shoes with spikes?

Ans. Spikes increase friction, providing a better grip on the ground.

33. Why is it harder to drag a mat when a person is sitting on it?

Ans. The added weight increases friction, making it harder to pull.

34. Define lubricant. Give some examples.

Ans. A lubricant is a substance that reduces friction between surfaces. Examples: Oil, grease, and wax.

35. Can friction be reduced to zero by polishing or excessive use of lubricants?

Ans. No, friction cannot be completely eliminated.

36. State the factors on which fluid friction depends.

Ans. Shape, speed, and viscosity of the fluid.

37. Why do kabaddi players rub their hands with soil?

Ans. To increase friction and improve grip.

38. Why must objects moving in fluids have special shapes?

Ans. To reduce fluid friction and allow smooth movement.

39. Fill in the blanks:

(a) Friction opposes the ----- between the surfaces in contact with each other.
(b) Friction occurs due to the -------between the two surfaces.
(c) Sliding friction is ----- than the static friction.

Ans.  (a) Friction opposes the motion between the surfaces in contact with each other.
(b) Friction occurs due to the roughness between the two surfaces.
(c) Sliding friction is less than the static friction.

Quick Views

 

Sound 

Class 9 

1. Sound and its Production

• Sound is a form of energy produced by vibrating objects.
• Example: Tuning fork, a stretched string, and vocal cords.
• A medium (solid, liquid, or gas) is required for sound to travel. Sound cannot travel in a vacuum.
• Sound waves are mechanical waves as they require a medium for propagation.

2. Propagation of Sound

• Sound propagates in the form of waves.
• These waves travel as compressions and rarefactions in a medium.
• Compression (C): Region of high pressure and high particle density.
• Rarefaction (R): Region of low pressure and low particle density.

Wave Motion in Sound

• Longitudinal waves: The particles of the medium vibrate parallel to the direction of wave propagation. Example: Sound waves.
• Transverse waves: The particles of the medium vibrate perpendicular to the direction of wave propagation. Example: Water waves, light waves. (Sound waves are not transverse!)

3. Characteristics of a Sound Wave

(a) Amplitude (A)

• The maximum displacement of particles from their mean position.
• Determines the loudness of the sound.
• More amplitude = Louder sound and less amplitude = Fainter sound.

(b) Frequency (f)

• Number of vibrations per second. Measured in Hertz (Hz).
• Determines the pitch of the sound.
• More frequency = High-pitched sound (e.g., whistle).
• Less frequency = Low-pitched sound (e.g., drum beat).

(c) Time Period (T)

• The time taken to complete one vibration (or one wave cycle).
• Formula: $$T = \frac{1}{f}$$
• SI Unit: Seconds (s).

(d) Wavelength (λ – Lambda)

• Distance between two consecutive compressions or rarefactions.
• Measured in meters (m).

(e) Wave Velocity (v)

• The speed at which sound waves travel in a medium.
• Formula: $$v = f \times \lambda$$
  
• Unit: m/s.

(f) Loudness

• Related to amplitude of the wave.
• Measured in decibels (dB).
• Threshold of hearing = 0 dB, normal conversation = 60 dB, jet engine = 130 dB.

4. Speed of Sound in Different Mediums

• Sound travels fastest in solids, slower in liquids, and slowest in gases.
• Speed of sound in different mediums at 25°C:
  • Air: 340 m/s
  • Water: 1450 m/s
  • Iron: 5000 m/s
  • Steel: 5130 m/s

5. Reflection of Sound

• Sound follows the laws of reflection, similar to light:
  1. Angle of incidence = Angle of reflection.
  2. The incident wave, reflected wave, and normal all lie in the same plane.
• Reflection of sound is used in SONAR and echolocation.

6. Echo and Reverberation

Echo

• When sound waves reflect from a surface and return to the listener after 0.1 seconds or more, an echo is heard.
• Minimum distance for an echo: 17.2 m (in air at 25°C).
• Examples of echoes:
  • Sound in an empty hall.
  • Echo in mountains or tunnels.

Reverberation

• Prolonged persistence of sound due to multiple reflections.
• Causes sound to become unclear in large halls.
• Reduced by:
  • Using soft materials like carpets, curtains, foam panels, etc.
  • Designing halls with sound-absorbing materials.

7. Applications of Sound

(a) SONAR (Sound Navigation and Ranging)

• Uses ultrasound to detect objects underwater.
• Principle: Ultrasonic waves reflect from underwater objects and return as echoes.
• Formula for calculating depth: $$\text{Distance} = \frac{\text{Velocity of Sound} \times \text{Time}}{2}$$
• Used in submarines, oceanography, and marine life study.

(b) Medical Uses of Ultrasound

• Ultrasound scanning: Used for imaging internal organs and fetus development.
• Lithotripsy: Used to break kidney stones using ultrasound waves.

(c) Bats and Echolocation

• Bats emit ultrasonic waves to detect objects and prey in the dark.
• They hear echoes to determine the distance and direction of objects.

8. Structure of the Human Ear

Parts of the Ear:

1. Outer Ear (Pinna): Collects sound and directs it to the eardrum.
2. Middle Ear: Contains three bones (malleus, incus, stapes) that amplify vibrations.
3. Inner Ear (Cochlea): Converts vibrations into electrical signals sent to the brain via the auditory nerve.

(A labeled diagram of the human ear should be included.)

9. Hearing Range and Ultrasound

• Humans: Can hear frequencies between 20 Hz – 20,000 Hz (Audible range).
• Infrasound (< 20 Hz): Elephants and whales communicate using infrasound.
• Ultrasound (> 20,000 Hz): Dogs, bats, and dolphins can hear these high-frequency sounds.

10. Why Do We See Lightning Before We Hear Thunder?

• Speed of light = $3 \times 10^8$ m/s (very fast).
• Speed of sound = 340 m/s (much slower).
• Thus, light reaches us before sound.

11. Pitch, Loudness, and Quality of Sound

• Pitch: Depends on frequency (higher frequency = higher pitch).
• Loudness: Depends on amplitude (higher amplitude = louder sound).
• Quality/Timbre: Determines how we differentiate between different sounds of the same pitch and loudness.

12. Noise vs. Music

Noise	Music
Unpleasant sound	pleasant sound
Irregular wave pattern	Regular wave pattern
Example: Horns, drills	Example: Musical instruments

13. Mechanical Nature of Sound Waves

• Sound waves are mechanical waves because they require a medium to travel.
• Unlike light, sound cannot travel in a vacuum.

Experiment to Prove Sound Needs a Medium (Bell Jar Experiment)

• A bell is placed inside a glass jar connected to a vacuum pump.
• When air is removed, the sound of the bell fades and eventually stops.
• This proves that sound cannot travel in a vacuum.

14. Laws of Sound Reflection

1. Angle of incidence = Angle of reflection.
2. Incident wave, reflected wave, and normal lie in the same plane.