PSEB CLASS 8 SCIENCE QUESTION PAPER 2024 WITH ANSWER KEY PDF DOWNLOAD
Question 1
(i) It is used to see different beautiful patterns
(a) Solar filter (b) Mirror (c) Telescope (d) Kaleidoscope
Answer: (d) Kaleidoscope
Explanation: A kaleidoscope is a toy with mirrors that creates beautiful patterns by reflecting light.
(ii) Charge is produced by transfer of
(a) Electrons (b) Protons (c) Atoms (d) Neutrons
Answer: (a) Electrons
Explanation: Charge is produced by the transfer of electrons from one atom to another. Protons and neutrons are the building blocks of atoms and do not carry a charge by themselves.
(iii) Which of these are epidemic?
(a) Dengue (b) Swine flu (c) Cholera (d) All of the above
Answer: (b) Swine flu
(iv) Which liquid is not a good conductor of electricity? ( Question different in Punjabi)
(a) Lemon juice (b) Distilled water (c) Common salt solution (d) Copper sulphate solution
Answer: (b) Distilled water
Explanation: Distilled water is a poor conductor of electricity because it has very few ions. Lemon juice, common salt solution, and copper sulphate solution are all good conductors of electricity because they contain ions that can move freely in the solution.
(v) This is a good conductor of electricity
(a) Bakelite (b) Rubber (c) PVC (d) Graphite
Answer: (d) Graphite
Explanation: Graphite is a good conductor of electricity because it is a form of carbon that has free-moving electrons. Bakelite, rubber, and PVC are all insulators, meaning they do not conduct electricity well.
(vi) Sound can travel in
(a) Gases only (b) Liquids only (c) Solids only (d) Gases, liquids and solids all
Answer: (d) Gases, liquids and solids all
Explanation: Sound waves can travel through all three states of matter: gases, liquids, and solids.
(vii) Which type of friction is greatest?
(a) Sliding friction (b) Rolling friction (c) Static friction (d) None of the above
Answer: (c) Static friction
Explanation: Static friction is the greatest type of friction because it requires the most force to overcome. Once the object starts moving, sliding friction takes over, which is usually less than static friction.
(viii) The hormone whose deficiency may cause diabetes is:
(a) Estrogen (b) Testosterone (c) Insulin (d) Thyroxine
Answer: (c) Insulin
Explanation: Insulin is a hormone produced by the pancreas that helps regulate blood sugar levels. A deficiency of insulin can lead to diabetes.
(ix) The fusion of sperm and egg produces:
(a) Zygote (b) Gamete (c) Embryo (d) Oviduct
Answer: (a) Zygote
Explanation: The fusion of sperm and egg is called fertilization, and it produces a zygote, which is the first stage of a new organism.
(x) International Biodiversity Day is celebrated on:
(a) 22nd February (b) 22nd March (c) 22nd April (d) 22nd May
Answer: (d) 22nd May
Explanation: International Biodiversity Day is celebrated on May 22nd.
(xi) Which of the following is an example of spontaneous combustion?
(a) Burning of petrol (b) Burning of magnesium ribbon (c) Burning of camphor (d) Burning of white phosphorous
Answer: (d) Burning of white phosphorous
Explanation: Spontaneous combustion is a type of combustion that can occur without an external ignition source. White phosphorous is a substance that can ignite spontaneously in air.
(xii) The best quality coal is:
(a) Peat (b) Lignite (c) Bituminous (d) Anthracite
Answer: (d) Anthracite
Explanation: Anthracite is the highest quality coal, with the highest amount of carbon and the fewest impurities.
(xiii) Which one of following cannot definitely be called living or non-living?
(a) Virus (b) Algae (c) Bacteria (d) Fungi
Answer: (a) Virus
Explanation: Viruses are considered to be on the borderline between living and non-living things. They can reproduce, but they cannot carry out their own metabolic processes.
(xiv) Which one of these can make its own food?
(a) Algae (b) Bread Mould (c) Diatom (d) Amoeba
Answer: (a) Algae
Explanation: Algae are autotrophs, which means they can make their own food using photosynthesis. Bread mold, diatoms, and amoebas are heterotrophs, which means they must obtain food from other organisms.
(xv) Earthworm is used for preparing
(a) Compost (b) Manure (c) Green manure (d) Vermicompost
Answer: (d) Vermicompost
Explanation: Vermicompost, also known as worm castings, is a nutrient-rich fertilizer that is produced by earthworms.
Match the following:
| Column A | Column B |
|---|---|
| (i) Black buck | (1) Used as fuel in kitchen |
| (ii) Fire extinguisher | (2) CO₂ |
| (iii) State mammal of Punjab | (3) Unwanted sound |
| (iv) Egg laying animals | (4) LPG |
| (v) Oviparous animals | (5) Transparent |
Answer Key:
(i) - (3) (ii) - (2) (iii) - (1) (iv) - (5) (v) - (4)
Match the columns:
- (1) Black buck (1) State mammal of Punjab
- (ii) Fire Extinguisher (2) CO₂
- (iii) _____ (3) Unwanted sound
- (iv) Egg laying animals (4) LPG
- (v) _____ (5) Ovi-parous animals
Fill in the blanks:
- (i) Crops grown in winter are called (Rabi) crops.
- (ii) Calorific value of LPG is (5500 kJ/kg).
- (iii) Binary fission occurs in (Amoeba).
- (iv) If the ovum is fertilized by sperm, a (Zygote) is formed.
- (v) Gravitation force is (Non-Contact) force.
- (vi) Friction on the bodies moving through fluids is called (Drag).
- (vii) Rubbing both hands produces (Heat) due to friction.
- (viii) Sound requires a (Medium) to travel.
- (ix) Covid-19 is a (Viral) disease.
- (x) Light can pass through (Transparent) bodies.
True/False:
- (i) Excessive use of fertilizers can turn soil acidic or basic. True
- (ii) All living organisms can be seen with naked eye. False
- (iii) CNG is more polluting than diesel. False (debate exists around this but it is not definitively true)
- (iv) Balanced diet is not essential for adolescents. False
- (v) Force of friction is non-contact force. False
Two Marks Questions (Do any twelve)
- What is a pest? Give examples.
- Name the major groups of micro-organisms.
- What are petrochemicals?
- List the conditions in which combustion can take place.
- What is red data book?
- Name various stages in life cycle of a butterfly.
- Define Adolescence.
- Write two methods to increase friction.
- What is difference between noise and music?
- What is an Epidemic?
- What is conductor? Give examples.
- Write some precautions for the safety of eyes.
- What is the difference between asexual and sexual reproduction?
- Why do electricians wear rubber shoes and rubber gloves?
- What is a poem? Give examples.
- Why is physical exercise important for adolescents?
- Water is not used to control fires involving electricity equipment. Why?
- Write some effects of electric current.
Three Marks Questions (Do any Seven)
- Write differences between manure and fertilizer.
- Write the tips advised by Petroleum Conservation Research Association (PCRA) to save petrol/diesel.
- Write various causes of deforestation.
- Give an activity to show that air exerts pressure.
- Friction is necessary evil, explain with example.
- List some methods to reduce noise pollution.
- What is a Kaleidoscope, what are its uses?
- With the help of a labelled diagram, explain the human eye.
- Explain how Vermicompost is prepared.
- How is paper made? How does the manufacturing of paper cause deforestation? What can you do to save paper?
