Olympiad Class 8 Science Mock Test Set 10

Question. Which of the following optical instruments use plane mirrors for viewing an object?
(A) Microscope
(B) Telescope
(C) Periscope
(D) Binocular
Answer : C

Question. Old news papers and other paper products were collected and treated to make toilet paper. What is this practice known as?
(A) Reducing
(B) Recycling
(C) Reusing
(D) Reinventing
Answer : B

Question. Which effect of current is responsible for a compass placed in an electric field to be deflected?
(A) Biochemical
(B) Magnetic
(C) Heating
(D) Chemical
Answer : B

Question. Which of these antibiotics is/are made from bacteria?
(A) Streptomycin
(B) Tetracycline
(C) Polio vaccine
(D) All of these
Answer : D

Question. Identify the force that tends to slow down the motion of a moving body.
(A) Magnetic force
(B) Frictional force
(C) Gravitational force
(D) Electric force
Answer : B

Question. Which of the following is NOT a conductor of electricity?
(A) Metallic coin
(B) Steel spoon
(C) Lid of a tin
(D) Piece of wood
Answer : D

Question. Which of the following happens when a wax candle is burnt?
(A) Fuel undergoes oxidation.
(B) Liberation of heat and light energy.
(C) Release of water vapour and carbon dioxide.
(D) All of the above
Answer : D

Question. Which of the following is not a precaution to be taken during lightning?
(A) Bathing should be avoided during thunderstorm
(B) Electrical appliances should be unplugged
(C) Metal pipes house should not be touched
(D) Electrical lights should not be switched on 
Answer : D

Question. Which of the following was used by Alexander Flemming to prepare an antibiotic to kill bacteria?
(A) Rhizopus
(B) Yeast
(C) Mushroom
(D) Penicillium notatum
Answer : D

Question. Which of the following produces a shrill but soft sound?
(A) Dog
(B) Lion
(C) Mosquito
(D) Fox
Answer : C

Question. During fractional distillation of petroleum where do the vapours with highest boiling point condense in the fractionating tower ?
(A) In upper portion
(B) In lower portion
(C) In middle portion
(D) Cannot be said
Answer : B

Question. A cube of side 0.2 m and weighing 100 N rests on the floor. What is the pressure exerted by the cube on the floor?
(A) 10 N m^-2
(B) 500 N m^-2
(C) 1000 N m^-2
(D) 2500 N m^-2
Answer : D

Question. How are earthworms useful to farmers?
(A) They help in nitrogen fixation in the soil.
(B) They help in killing pests.
(C) They make the soil airy, soft and fertile.
(D) They help in pulling out of weeds.
Answer : C

Question. According to the laws of reflection, which of the following statements is correct?
(A) Angle ‘i’ is greater than angle ‘r’
(B) Angle ‘i’ is less than angle ‘r’
(C) Angle ‘i’ is equal to angle ‘r’
(D) Both (A) and (B)
Answer : C

Question. What is the best method to avoid pollution by using plastic bags?
(A) Bury the plastic bags in the soil
(B) Use biodegradable plastic bags
(C) Throw the plastic bags into the river
(D) Burn the plastic bags in a rubbish dump
Answer : B

Question. Why is zinc better than tin if we want to protect a piece of iron from rusting by electroplating ?
(A) Zinc is cheaper than tin.
(B) Tin is toxic.
(C) Zinc prevents contact of iron with water, air.
(D) Rusting is prevented even when the zinc layer is broken.
Answer : D

Question. Which of these is NOT a major group of activities for improving crop yield?
(A) Crop protection management
(B) Crop production management
(C) Crop variety improvement
(D) Crop transport management
Answer : D

Question. Which of the things will not happen in the world if friction were not present?
(A) Dentist drilling the teeth.
(B) Carpenter smoothening a wooden block.
(C) Motion of cars on road.
(D) All of the above
Answer : D

Question. The charges present on the various objects are as shown in the figure below. In which of the following cases, a force of repulsion acts between them?

Answer : A

Question. X is the reproductive cell produced in Y of a female organism while Z is the reproductive cell that is produced in the testes of a male organism. What can X, Y and Z be?

Answer : A