Olympiad Class 8 Science Mock Test Set A

Question. Which part of the human eye controls the focus of the eye by varying its thickness?
(A) Ciliary muscles
(B) Iris
(C) Pupil
(D) Retina
Answer : A

Question. Polythene is produced by
(A) isomerization
(B) polymerisation
(C) hydrogenation
(D) all of the above
Answer : B

Question. Which of the following is a good conductor of electricity?
(A) Solid NaCl
(B) Vinegar
(C) Distilled water
(D) Liquid oxygen
Answer : B

Question. Which of these build the hive, collect nectar and pollen, clean the cells and protect the hive?
(A) Queen bee
(B) Worker bee
(C) Drone
(D) Male bee
Answer : B

Question. Which figure shows the correct direction of frictional force when a wooden block is moving up on an inclined plane?

Answer : A

Question. Which substance can be used to put out fires?
(A) Wood
(B) Petrol
(C) Sand
(D) Kerosene
Answer : C

Question. Which among the following is a dark coloured, viscous, strong smelling liquid?
(A) Kerosene
(B) Alcohol
(C) Petroleum
(D) All of these
Answer : C

Question. When an uncharged body touches a charged body, then what happens?
(A) It acquires a similar charge as the charged body.
(B) It acquires an equal but opposite charge.
(C) A charged body gains some charge from an uncharged body.
(D) The uncharged body remains uncharged.
Answer : A

Question. The organic manure is considered better than fertilisers because
(A) it can be prepared in the factories.
(B) it is less rich in plant nutrient.
(C) it improves the texture of the soil.
(D) it decreases the water holding capacity of the soil.
Answer : C

Question. In which of the following media does the sound travel with least speed?
(A) liquids
(B) Solids
(C) Gases
(D) Semi-solids
Answer : C

Question. Fresh endometrium is formed every month in
(A) ovary.
(B) ureter.
(C) urethra.
(D) uterus.
Answer : D

Question. Which of the following is not a force?
(A) Water in rivers flowing downwards.
(B) Density of an iron object.
(C) Tension of a rope.
(D) Air resistance against a moving bicycle.
Answer : B

Question. Which of the following shows a modern technology measure used to preserve and conserve the environment?
(A) Practising crop rotation
(B) Using leaded petrol in motor vehicles
(C) Using machines in agricultural industry
(D) Converting biological wastes into biogas
Answer : D

Question. What are the characteristics of light used in a periscope?
(A) Light can be reflected
(B) Light travels in straight lines
(C) Light can be refracted
(D) Both (A) and (B)
Answer : D

Question. Identify the harmful radiations emitted by the sun.
(A) Ultra violet
(B) Infra red
(C) Visible
(D) Radio waves
Answer : A

Question. A metal spoon has to be coated with copper using electricity. The metal spoon should be
(A) made the cathode
(B) made the anode
(C) made the key
(D) made the electrolyte
Answer : A

Question. What may happen due to improper methods of disposal of plastic wastes by burning or throwing them into rivers?
(i) Endanger the lives of aquatic plants and animals.
(ii) Causes air pollution.
(iii) Damages our immune system.
(A) (i) and (ii) only
(B) (ii) and (iii) only
(C) (i) and (iii) only
(D) (i), (ii) and (iii)
Answer : A

Question. The information given in the box is about the organelles present in a cell.
I. Cytoplasm II. Cell wall III. Nucleus IV. Chloroplast
The above cell cannot be an animal cell because of the presence of which of the following cell organelles ?
(A) I and II only
(B) II and III only
(C) II and IV only
(D) I and IV only
Answer : C

Question. Why does smoothening a surface in contact beyond a certain limit raises friction?
(A) Actual area of contact increases.
(B) Surface irregularities are increased.
(C) Surface projections are sharpened.
(D) Decrease in weight of object.
Answer : C

Question. Which property of coke makes it useful in the manufacture of steel?
(A) Availability in pure form.
(B) Toughness.
(C) Porosity.
(D) Ability to act as reducing agent.
Answer : D