HBSE Class 9 Science Question Paper 2021 Answer Key
Q1. What does the Odometer of a car measures ?
(A) Only Speed
(B) Acceleration of the car
(C) Distance covered by the car
(D) None of the above
Ans. (C) Distance covered by the car
Q2. What is the quantity which is measured by the area occupied below the velocity-time graph ?
(A) Time
(B) Displacement
(C) Velocity
(D) Acceleration
Ans. (B) Displacement
Q3. The natural tendency of objects to resist a change in their state of rest or of uniform motion is called :
(A) inertia
(B) Force
(C) Momentum
(D) Balanced force
Ans. (A) inertia
Q4. The S. I. unit of force is :
(A) Newton
(B) Newton per second
(C) Newton-Meter
(D) Newton/Meter
Ans. (A) Newton
Q5. Weight of a body on Moon is ………….. of its weight on earth.
(A) 1/3
(B) 1/4
(C) 1/6
(D) 3/4
Ans. (C) 1/6
Q6. Force of gravitation due to the earth is called :
(A) Density
(B) Pressure
(C) Gravity
(D) Thrust
Ans. (C) Gravity
Q7. Which form of energy does the flowing water possess ?
(A) Potential Energy
(B) Electrical Energy
(C) Gravitational Energy
(D) Kinetic Energy
Ans. (D) Kinetic Energy
Q8. In which of the media, does sound travel the fastest ?
(A) iron
(B) Air
(C) Water
(D) All of the above
Ans. (A) iron
Q9. The number of complete oscillations per unit time is called …………..
(A) Amplitude
(B) Frequency
(C) Wavelength
(D) Time period
Ans. (B) Frequency
Q10. The state of water at 100°C is :
(A) Solid
(B) Liquid
(C) Gas
(D) Both Liquid & Gas
Ans. (D) Both Liquid & Gas
Q11. Which of the following are matter ?
(A) Chair
(B) Almonds
(C) Air
(D) All of the above
Ans. (D) All of the above
Q12. Which of the following will show ‘Tyndall effect’ ?
(A) Salt Solution
(B) Milk
(C) Starch Solution
(D) Soda Water
Ans. (B) Milk
Q13. The technique to separate butter from curd is :
(A) Evaporation
(B) Centrifugation
(C) Sublimation
(D) Chromatography
Ans. (B) Centrifugation
Q14. What is the symbol of element Barium ?
(A) B
(B) Be
(C) Bm
(D) Ba
Ans. (D) Ba
Q15. Atomic mass of Oxygen is :
(A) 12
(B) 14
(C) 16
(D) 23
Ans. (C) 16
Q16. 1 mole (of anything) = ………….. (in number).
(A) 6.022
(B) 6.002 × 10²³
(C) 6.022 × 10²³
(D) 6.002 × 10³²
Ans. (C) 6.022 × 10²³
Q17. The sub-atomic particles of an atom are :
(A) Protons
(B) Neutrons
(C) Electrons
(D) All of the above
Ans. (D) All of the above
Q18. Who discovered cells ?
(A) Robert Hooke
(B) Robert Brown
(C) Leeuwenhoek
(D) T. Schwann
Ans. (A) Robert Hooke
Q19. Where are proteins synthesized inside the cell ?
(A) In Ribosomes
(B) In Mitochondria
(C) In Plastids
(D) None of these
Ans. (A) In Ribosomes
Q20. Which tissue is responsible for movement in our body ?
(A) Nervous Tissue
(B) Parenchyma
(C) Epithelium Tissue
(D) Muscle Tissue
Ans. (D) Muscle Tissue
Q21. Arthropoda animal is :
(A) Ostrich
(B) Scorpion
(C) Chameleon
(D) Sea horse
Ans. (C) Chameleon
Q22. The meaning of Porifera is :
(A) Reptiles
(B) Amphibians
(C) Organisms with holes
(D) Stream lined
Ans. (C) Organisms with holes
Q23. The heart of Crocodile is :
(A) Two-Chambered
(B) Three-Chambered
(C) Four-Chambered
(D) None of the above
Ans. (C) Four-Chambered
Q24. Infectious disease spread by :
(A) Water
(B) Air
(C) Vector Insects
(D) All of the above
Ans. (D) All of the above
Q25. AIDS is caused by :
(A) Bacteria
(B) Virus
(C) Protozoa
(D) Fungus
Ans. (B) Virus
Q26. What is the percentage of Nitrogen gas in our atmosphere ?
(A) 70%
(B) 78%
(C) 50%
(D) 20%
Ans. (B) 78%
Q27. In which of the following Carbon is present ?
(A) Protein
(B) Carbohydrates
(C) Lipid
(D) All of the above
Ans. (D) All of the above
Q28. Which of the following is a ‘green house gas’ ?
(A) Nitrogen
(B) Oxygen
(C) Carbon dioxide
(D) All of the above
Ans. (C) Carbon dioxide
Q29. Which of these is enriched in protein ?
(A) Black gram
(B) Gram
(C) Peas
(D) All of the above
Ans. (D) All of the above
Q30. Which of the following is Indian cow breed ?
(A) Red Sindhi
(B) Brown Swiss
(C) Aseel
(D) Leghorn
Ans. (A) Red Sindhi
Q31. A racing car has a uniform acceleration of 4 metre/sec². What distance will it cover in 10 sec. after start ?
Ans. Acceleration (a) = 4 m/sec²
Time period (t) = 10 sec
The car has uniform acceleration. This means that initially, it was in rest. Thus,
Initial velocity (u) = 0
As per the second equation of motion,
s = ut + ½at²
s = 0×10 + ½×4×10²
s = 200 metres
Therefore, the car will cover a distance of 200m in 10sec after start.
Q32. Write two differences between Mixture and Compound.
Ans. Mixtures– Mixtures are impure substances. They are made up of two or more substances mixed physically. The constituents of a mixture are present in varying ratios. Mixtures do not have fixed properties. Their properties depend on the nature of their components and the ratios in which they are combined.
Compounds– Compounds are pure substances. They are made up of two or more elements combined chemically. The constituents of a compound are present in a fixed ratio. Compounds have fixed properties. For example, a particular compound will have fixed temperatures at which it melts and boils.
Q33. State any two conditions essential for good health.
Ans. Nutritious food, Clean environment and Personal hygiene.
Q34. (i) When a carpet is beaten with a stick, dust comes out of it. Explain.
Ans. According to Newton’s first law of motion, the dust particles stay in a state of rest, while the carpet moves. Hence, the dust particle comes out of the carpet due to inertia.
(ii) Write the Newton’s Third Law of Motion.
Ans. Newton’s Third Law of Motion states that for every action (force) in nature there is an equal and opposite reaction. If object A exerts a force on object B, object B also exerts an equal and opposite force on object A.
Q35. Write the chemical formulae of the following :
(i) Magnesium Chloride
Ans. MgCl2
(ii) Copper Nitrate
Ans. Cu(NO3)2
(iii) Hydrogen Sulphide
Ans. H2S
Q36. Make a comparison and write down ways in which ‘plant cells’ are different from ‘animal cells’.
Ans. Plant Cell– They are larger in size. Cell wall is present. Lysosomes are absent or very few in number. Plastids are present. Subunits of Golgi bodies known as dictyosomes are present. Vacuoles are larger in size.
Animal Cell– They are smaller in size. Cell wall is absent. Lysosomes are larger in number. Plastids are absent. Prominent Golgi bodies are present. Vacuoles are smaller in size.
Q37. (i) A bulb consumes 500 J of electrical energy in 10 sec. What is its power ?
Ans. Energy (E) = 500 J
Time (t) = 10 sec
Power (P) = Energy(E)÷Time(t)
P = E/t = 500/10 = 50 watts