CBSE Class 8 Science NSO Olympiad MCQs with Answers Set J

LOGICAL REASONING

Question. Find the figure from the options which will continue the same series as established by the Problem Figures.

Answer : A

Question. If in a certain code language, ‘men are very busy’ is written as ‘1234’, ‘busy persons need encouragement’ is written as ‘4567’, ‘encouragement is very important’ is written as ‘3589’ and ‘important persons are rare’ is written as ‘2680’, then how will ‘encouragement’ be written in that language?
A. 5
B. 6
C. 8
D. 9
Answer : A

Question. Select the correct water image of the given figure.

Answer : A

Question. How many pairs of letters are there in the word ‘CONTEMPORARY’ which have as many letters between them in the word as in the English alphabets?
A. Three
B. Two
C. Four
D. More than four
Answer : D

Question. Two positions of a dice are given. What number will be on the face opposite to the face having number 5?

A. 1
B. 3
C. 4
D. 2
Answer : C

Question. Dilip’s position from the left in a row of students is 10th and Jagdish’s position is 20th from the right.
Both of them interchange their positions and Jagdish becomes 23rd from the right. How many students are there in the row?
A. 33
B. 44
C. 32
D. 42
Answer : C

Question. There is a certain relationship between the figures (i) and (ii). Establish the same relationship between the figures (iii) and (iv) by selecting a suitable figure from the options which will replace the (?) in figure (iv).

Answer : B

Question. If ‘D’ denotes ‘equal to’; ‘ ’ denotes ‘not equal to’; ‘+’ denotes ‘greater than’; ‘–’ denotes ‘less than’; ‘×’ denotes ‘not greater than’; ‘÷’ denotes ‘not less than’ then a – b – c implies _______.
A. a – b + c
B. b + a – c
C. c × b + a
D. None of these
Answer : D

Question. If ‘A × B’ means that ‘A is the sister of B’, ‘A ÷ B’ means that ‘A is the daughter of B’, ‘A – B’ means that ‘A is the son of B’, then how is P related to S in relationship P – Q × R ÷ S ?
A. Brother
B. Son
C. Grandson
D. None of these
Answer : C

Question. Count the number of triangles in the given figure.

A. 25
B. 23
C. 27
D. None of these
Answer : D

SCIENCE

Question. The diagram shows what happens when weights of different masses are placed on the same spring.

Which of the following is the original length of the spring?
A. 20 cm
B. 26 cm
C. 36 cm
D. 50 cm
Answer : C

Question. Which of the following light rays behaves correctly when it passes through the converging lens?

A. I
B. II
C. III
D. IV
Answer : C

Question. The speed-time graphs Speed (m s^–1) for three moving vehicles
I, II and III are shown here. If x, y and z are the distances travelled by I,
II and III respectively in 8 s, then which of the following comparisons is correct?

A. x > y = z
B. x > y > z
C. x = y < z
D. x < y < z
Answer : A

Question. Arrange the following planets in decreasing order of time required to complete one revolution around the sun.
(i) Earth (ii) Uranus (iii) Mars (iv) Jupiter
A. (i), (ii), (iii), (iv)
B. (i), (iii), (iv), (ii)
C. (iv), (iii), (ii), (i)
D. (ii), (iv), (iii), (i)
Answer : D

Question. The given figure shows a gas trapped in part X of an apparatus containing mercury.
If the atmospheric pressure is 760 mm Hg, then what is the pressure of the gas?

(Figure is not drawn to the scale.)
A. 80 mm Hg
B. 150 mm Hg
C. 300 mm Hg
D. 910 mm Hg
Answer : D

Question. Three plotting compasses are placed close to a current carrying wire wrapped around an insulator as shown in the figure.

How many compass needles will change direction if the current through the wire is increased? (Ignore the effect of the earth’s magnetic field.)
A. 0
B. 1
C. 2
D. 3
Answer : A

Question. Consider the given statements and select the option which correctly identifies true (T) and false (F) ones.
(i) When a body is in steady motion on a surface, the force of friction is dynamic friction.
(ii) The force of friction between two bodies always acts parallel to the surfaces in contact with each other.
(iii) It is easier to push a lawn roller than to pull.
(iv) Limiting friction is greater than sliding friction.
    (i)    (ii)    (iii)    (iv)
A. T      F       T       F
B. F      T       F       T
C. T      T       T       F
D. T      T       F       T
Answer : D

Question. Match column I with column II and select the correct option from the given codes :
   Column I                             Column II
P. Bulb                        (i) Chemical effect of current
Q. Electrolyte             (ii) Heating effect of current
R. Electroplating        (iii) Conducting solution
A. P - (i), Q - (ii), R - (iii)
B. P - (iii), Q - (i), R - (ii)
C. P - (i), Q - (iii), R - (ii)
D. P - (ii), Q - (iii), R - (i)
Answer : D

Question. What is the best thing to do when strong winds are blowing over a hut having a weak thatched roof ?
A. Open the doors and windows.
B. Close the doors and windows.
C. Make holes in the roof.
D. Burn wood inside.
Answer : A

Question. A body goes 20 km east, then 10 km north, then 50 km west and then 30 km east. Find the displacement of the body from the initial position.
A. 0 km
B. 20 km
C. 10 km
D. 110 km
Answer : C

Question. Read the given statements and select the correct option.
Statement 1 : The amount of heat produced in a current carrying wire does not depend on its material.
Statement 2 : If a large current passes through the filament of an electric bulb, then the filament may become so hot that it may even melt and break.
A. Both statements 1 and 2 are true and statement 2 is the correct explanation of statement 1.
B. Both statements 1 and 2 are true but statement 2 is not the correct explanation of statement 1.
C. Statement 1 is true and statement 2 is false.
D. Statement 1 is false and statement 2 is true.
Answer : D

Question. David is observing his image in a plane mirror. The distance between the mirror and his image is 4 m. If he moves 1 m towards the mirror, then the distance between David and his image will be
A. 3 m
B. 5 m
C. 6 m
D. 8 m
Answer : C

Question. A laboratory thermometer gave the reading of –1°C and 99°C when inserted into melting ice and boiling water respectively, both at standard atmospheric pressure. What is the error when the same thermometer is used to measure the difference between two arbitrary temperatures?
A. –1°C
B. 1°C
C. 0°C
D. 2°C
Answer : C

Question. An object of weight W is pulled along a rough horizontal surface by a force F. The force of friction is Fr. Which diagram correctly shows the direction of these forces on the object?

Answer : C

Question. Match column I with column II and select the correct option from the given codes.

A. P - (ii), Q - (iii), R - (v), S - (i), T - (iv)
B. P - (v), Q - (iv), R - (ii), S - (i), T - (iii)
C. P - (v), Q - (ii), R - (iv), S - (i), T - (iii)
D. P - (i), Q - (ii), R - (iii), S - (iv), T - (v)
Answer : B

Question. Match column I with column II and select the correct option from the given codes.
    Column I               Column II
P. Kerosene            (i) Road surfacing
Q. Paraffin wax      (ii) Fuel for vehicles
R. Bitumen            (iii) Manufacturing candles
S. Gasoline           (iv) Jet engine fuel
A. P-(ii); Q-(iv); R-(iii); S-(i)
B. P-(iii); Q-(ii); R-(iv); S-(i)
C. P-(iv); Q-(ii); R-(i); S-(iii)
D. P-(iv); Q-(iii); R-(i); S-(ii)
Answer : D

Question. Priya, a class 8 student collected following items (i-vi) and tested them with different indicators :
(i) Toothpaste (ii) Vinegar
(iii) Curd (iv) Lemon
(v) Baking soda (vi) Limestone
Fill in the blanks by selecting an appropriate option.
She observed that with p , methyl orange indicator turned yellow while with q , China rose indicator turned magenta.
             p                     q
A. (ii), (iii), (iv)      (i), (v), (vi)
B. (i), (iv), (vi)      (ii), (iii), (v)
C. (i), (v), (vi)      (ii), (iii), (iv)
D. (ii), (iv), (v)      (i), (iii), (vi)
Answer : C

Question. Read the given statements and select the correct option.
Statement 1 : Petroleum is a fossil fuel.
Statement 2 : Kerosene is not obtained as a fraction of fractional distillation of petroleum.
A. Both statements 1 and 2 are true and statement 2 is the correct explanation of statement 1.
B. Both statements 1 and 2 are true but statement 2 is not the correct explanation of statement 1.
C. Statement 1 is true and statement 2 is false.
D. Both statements 1 and 2 are false.
Answer : C

Question. Savita had four metals : iron, zinc, X and Y. She arranged the following experimental set-ups and observed that displacement reaction took place in each case

Metals X and Y are respectively
A. Al and Ag
B. Cu and Mg
C. Ag and Cu
D. Cu and Ag
Answer : D

Question. Select the correct option for the given statements.
I. Plastics are generally good conductors of electricity.
II. Ropes made by bakelite are used in cranes and elevators.
III. Teflon is a special plastic on which oil and water do not stick.
IV. Plastic is non-biodegradable, hence not environment friendly.
        I              II             III            IV
A. True        True        False      False
B. False       False      True       True
C. True        False      True        False
D. False      True        False      True
Answer : B

Question. Ms. Ruchi, a class 8 teacher heated five different substances (I-V) in air and tabulated her observations as follows :

Identify the types of changes these substances have undergone and select the correct option. Physical change Chemical change
A. II, III and IV I and V
B. I and II III, IV and V
C. I and V II, III and IV
D. II and V I, III and IV
Answer : C

Question. Which of the following statements is/are correct?
I. LPG is non-flammable substance, that is why it is used for cooking at our homes.
II. On burning, camphor produces flame while charcoal does not produce flame.
III. Sulphur is a non-combustible non-metal.
IV. Combustion of phosphorus is an example of rapid combustion.
A. II and IV only
B. II only
C. I, III and IV only
D. None of these
Answer : B

Question. Study the given Venn diagram carefully and fill in the blanks

Answer : D

Question. Read the given paragraph where few words have been italicised.
Pituitary gland is located just below hypothalamus and controls the activity of other glands. Thyroid gland is located in front of the neck. It secretes hormone thyroxine which regulates metabolism. Parathyroid gland secretes hormone calcitonin that regulates level of calcium in blood. Adrenal glands are paired glands present on top of each ovary. They secrete hormone parathormone.
Select the correct option regarding these.
A. Neck and thyroxine should not be replaced as they are correctly mentioned.
B. Calcitonin should be replaced with insulin.
C. Ovary and parathormone should not be replaced as they are correctly mentioned.
D. Hypothalamus must be replaced by medulla oblongata.
Answer : A

Question. Refer to the given figure regarding  zonation in terrestrial biosphere reserve and select the correct option.

Answer : A

Question. After vigorous exercise, changes occur in the muscle tissue. Compared with ‘at rest’ conditions what will the changes be?
     Glycogen               ATP               Lactate                 pH
A. Decreased         Decreased        Increased          Decreased
B. Decreased         Increased          Increased          Increased
C. Increased          Increased          Increased          Increased
D. Increased          Decreased        Decreased         Increased
Answer : A

Question. The given box shows some rabi and kharif crops.
Identify these crops and select the option that correctly categorises them.
Sugarcane, Cotton, Mustard, Maize, Sorghum, Linseed, Barley, Groundnut, Wheat, Chickpea, Soybean
A. Rabi - Wheat, Barley, Linseed, Cotton, Maize
Kharif - Sugarcane, Mustard, Groundnut, Soybean, Chickpea, Sorghum
B. Rabi - Mustard, Linseed, Barley, Wheat, Chickpea 
Kharif - Sugarcane, Cotton, Maize, Sorghum, Groundnut, Soybean
C. Rabi - Sugarcane, Linseed, Groundnut, Wheat, Soybean
Kharif - Mustard, Cotton, Barley, Sorghum, Chickpea, Maize
D. Rabi - Wheat, Barley, Sugarcane, Sorghum, Chickpea
Kharif - Linseed, Soybean, Mustard, Cotton, Groundnut, Maize
Answer : B

Question. Refer to the given diagram.

Select the correct option regarding this.
A. Organism A is hermaphrodite or bisexual and may undergo either self or cross fertilisation.
B. Organisms I and II are unisexual and exhibit external fertilisation.
C. Organism A could be Taenia if it undergoes self fertilisation or it could be earthworm if it undergoes cross fertilisation.
D. All of these
Answer : D

Question. Which of the given containers will continue to have healthy fish and plants at the end of a week?

Answer : A

Question. Read the given paragraph.
The cytoplasm of the cells of a tomato plant contains organelle X which is of several types. Type Y is present in leaves of plant and imparts green colour whereas type Z is present in fruits of plant and imparts red colour.
Select the option which correctly identifies X, Y and Z.
         X                      Y                            Z
A. Plastid          Leucoplast             Chromoplast
B. Plastid          Chloroplast            Chromoplast
C. Plastid          Chloroplast            Leucoplast
D. Plastid          Chromoplast          Chloroplast
Answer : B

Question. Refer to the given figure and select the incorrect option.

A. Self pollination is not possible in a flower that lacks either X or Y.
B. Monoecious plants like maize bear two types of flower, one with X and other with Y.
C. W and Z constitute non-essential floral whorls.
D. Plants with flowers having both X and Y can never undergo cross pollination.
Answer : D

Question. Refer to the given set-up.

Answer : D

Question. Read the given statements and select the option that correctly fills the blanks in any two of them
(a) Zygote divides a number of times and forms a hollow ball like structure called (i) . It moves down and gets implanted in the uterus. It starts developing body parts and at this stage it is called (ii) .
(b) (iii) is the period in life when a girl or a boy attains sexual maturity.
(c) Production of sex hormones is under the control of (iv) gland.
(d) Metamorphosis in frog requires presence of (v) in water to produce thyroxine hormone.
A. (i) - Fetus, (iv) - Thymus
B. (ii) - Embryo, (iv) - Pituitary
C. (iii) - Adolescence, (v) - Calcium
D. (ii) - Fetus, (iii) - Senescence
Answer : B

Question. The given table describes the amount of pollutants in body of aquatic organisms in a river.

Select the option that correctly arranges these organisms in a food chain.
A. Q→S→P→T→R
B. R→T→P→S→Q
C. T→P→Q→S→R
D. R→P→T→Q→S
Answer : B

Question. Rahul conducted an experiment to calculate percolation rate of three soil samples X, Y and Z and tabulated his results as follows

Identify soils X, Y and Z and select the incorrect option regarding them.
A. Soil Y is abundantly found in those areas where plants with thick, fleshy and photosynthetic stems are present.
B. Soil Z is abundantly found in those areas where plants with aerial breathing roots are present.
C. Soil X is best suited for growth of wheat and maize.
D. None of these
Answer : D

​​​ACHIEVERS SECTION

Question. Identify the given organisms (P-S) and select the incorrect option regarding them.

A. P could be an eukaryotic organism that causes abdominal discomfort in man.
B. Q could be a prokaryotic organism that helps in breakdown of dead bodies of plants and animals.
C. Organism R could be used to obtain antibiotics.
D. S could be an organism that causes sleeping sickness in humans.
Answer : B

Question. Refer to the given dichotomous key and select the correct option regarding cell organelles L - O.
I. (a) Cell organelle bounded by double membrane - Go to II
(b) Cell organelle bounded by single membrane - Go to III
II. (a) Directs cell growth and controls its activities - L
(b) Provides colour to flowers and fruits - M
III. (a) Removes dead cells and digests foreign material - N
(b) Carries out some oxidative reactions in a cell - O
A. L could be mitochondria whereas M could be chloroplast.
B. M could be chromoplast whereas N could be Golgi apparatus.
C. L could be nucleus whereas O could be peroxisome.
D. M could be leucoplast whereas N could be vacuole.
Answer : C

Question. The given figure represents the fractionating column used in refining of petroleum.

Which of the following statements about the fractions X, Y and Z is/are incorrect?
I. The order of their densities is X > Y > Z.
II. The fraction Z will condense first and the fraction X will condense at the last.
III. The order of their boiling points is X < Y < Z.
IV. X can be heavy oil, Y can be light oil while Z can be gasoline and naphtha.
A. I and IV only
B. I only
C. II and III only
D. None of these
Answer : A

Direction (Q. No. a and b) : Read the given passage and answer the following questions.

The figure shows a pendulum

Deepak wanted to find out the time taken by the pendulum to make a complete swing as shown in the figure. He adjusted the factors used in the experiment. The time period of a simple pendulum is calculated by using T = 2π√l/g
where l = length of pendulum, g = 980 cm/s². He then tabulated his results in the following table

Question a. To find out how the difference in the mass of the pendulum bob would affect the time taken for the pendulum bob to make a complete swing, which two set-ups should Deepak use for comparison?
A. Set-ups I and III
B. Set-ups I and IV
C. Set-ups II and V
D. Set-ups III and V
Answer : D

Question b. Which of the following graphs best represents the variation of T² with l?

Answer : A