Olympiad Class 9 Science Mock Test Set D

Question. A rainbow is formed as a result of the
(A) absorption of sunlight by the raindrops
(B) reflection of sunlight by the raindrops
(C) dispersion of sunlight by the raindrops
(D) diffraction of sunlight by the raindrops
Answer : C

Question. Which of the following can also be made with the material used to make the tent that can be used in rainy season also?
(A) An umbrella
(B) A raincoat
(C) A water container
(D) All of the above
Answer : D

Question. If the iron key has to be coated with a red deposit on it, which of the given solutions has to be used during electrolysis?
(A) Copper (II) sulphate
(B) Aluminium nitrate
(C) Iron (II) sulphate
(D) Silver chloride
Answer : A

Question. Which of the following exhibit the characteristics given below?
X – Form a green scum over wet soil
Y – Closer to bacteria
Z – Pigments mask the chlorophyll
(A) Lichens
(B) Volvox
(C) Blue green algae
(D) Spirogyra
Answer : C

Question. What kind of combustion is undergone by ignition of a cracker?
(A) Explosive
(B) Spontaneous
(C) Rapid
(D) Slow
Answer : A

Question. Birds can fly in the air because they
(A) are small
(B) are lighter than air
(C) push more air behind
(D) all of these
Answer : C

Question. If an ebonite rod rubbed with fur and a glass rod rubbed with silk cloth are brought nearer to each other, then what happens?
(A) They will attract each other.
(B) They will repel each other.
(C) Nothing will happen to them.
(D) They will get heated up.
Answer : A

Question. Identify the beneficial activities of bacteria.
(A) The digestion of cellulose in herbivores
(B) The production of antibiotics
(C) The decomposition of waste matter
(D) All of the above
Answer : D

Question. Why is sound heard when a ball strikes the floor?
(A) The air particles from the floor flow into our ears.
(B) The air particles from the floor vibrate and pass into our ears.
(C) The air particles vibrate and touch the floor
(D) The wavelength of the sound wave is large enough to produce the sound.
Answer : B

Question. Why is more care needed to preserve petrol than coal?
(A) Petrol has high calorific value
(B) Coal has low calorific value
(C) Petrol has low ignition temperature
(D) Coal undergoes complete combustion
Answer : C

Question. The speed of a falling body increases continuously. This is because
(A) no force acts on it
(B) it is very light
(C) the air exerts a frictional force on it
(D) the earth attracts it
Answer : D

Question. The figure given below shows an amoeba that has been sliced into four parts. Which of the following labelled parts can still live and reproduce?

(A) P
(B) Q
(C) R
(D) S
Answer : C

Question. Based on the figure given, find the angle of reflection.

(A) 40°
(B) 0°
(C) 50°
(D) Data insufficient
Answer : C

Question. Which of the following fibres is used for rock climbing and in parachutes?
(A) Nylon
(B) Cotton
(C) Jute
(D) Silk
Answer : A

Question. What happens when electric current is passed through a conducting solution?
(A) A change of state occurs
(B) A chemical reaction takes place
(C) An explosion occurs
(D) Both (A) and (C)
Answer : B

Question. In which of the following processes is weeds are removed from crops ?
(A) Weeding
(B) Threshing
(C) Harvesting
(D) Winnowing
Answer : D

Question. Why tyres are made circular in shape?
(A) It is easy to inflate them.
(B) Rolling friction is less than sliding friction.
(C) Circular tyres dissipate less heat.
(D) It is easy to slow down or stop vehicle.
Answer : B

Question. Which of the following is NOT a property of copper?
(A) Ductile
(B) Malleable
(C) Low melting point
(D) Good conductor of heat
Answer : C

Question. When we remove polyester or woollen clothes in the dark, we see a spark and hear a crackling sound. Why does it occur?
(A) Static electricity.
(B) Current electricity.
(C) Reflection of light.
(D) Refraction of light.
Answer : A

Question. Identify a major group of activity that is used for improving the yield of crop?
(A) Crop protection management
(B) Crop production management
(C) Crop variety improvement
(D) All of the above
Answer : D