Science Olympiad Model Test Paper - 2 | Science Olympiad Class 9 PDF Download

Ans: (a)
In one step, the figure gets laterally inverted and one line segment is lost from the upper end of the RHS portion of the figure. In the next step, the figure gets laterally inverted and one line segment is lost from the upper end of the LHS portion of the figure.

Ans: (b)

• From the statements, we know that D is greater than E (D – E), E is less than or equal to F (E ÷ F), and F is equal to G (F × G).
• From E ÷ F, we can conclude that E is either less than or equal to F, and since F is equal to G, E must also be less than or equal to G (E ÷ G).
• However, we cannot definitively conclude that D is less than or equal to G because D is greater than E, and we don't have a direct comparison between D and G.
• Thus, only conclusion I (E ÷ G) is true, while conclusion II (D ÷ G) is not necessarily true.

Ans: (c)
Only in fig. (3), the two shaded portions lies on the same side of the main line.

Ans: (d)

• Step I: The machine will rearrange the words to form "steady slow and wins the race".
• Step II: Next, it will change the order to "steady wins slow and the race".
• Step III: Then, it will adjust to "steady wins the slow and race".
• Step IV: Finally, it will produce "steady wins the race slow and". This is the last step.

Ans: (b)
Only son of Salman’s mother’s father - Salman’s maternal uncle.
So, the girl’s maternal uncle is Salman's maternal uncle.
Thus, the girl’s mother is Salman’s aunt.

Ans: (c)

• M is the son of N and is married to P.
• S is P's sister, making M and S brothers-in-law.
• H is married to S, which means H is also M's brother-in-law.
• Thus, the correct answer is that H is M's brother-in-law.

Ans: (c)
The number of sides of the central figure increases by one and the number of line segments attached to the central figure decreases by one.

Ans: (d)
Clearly, even both I and II together do not reveal the exact time of departure of the train today.

Ans: (d)
Man lives on Earth and earth called a comet. So, the correct answer is a comet.

Ans: (b)

• From the information, we know that P is going to Chandigarh and is not an officer.
• S is going to Mumbai and is a doctor.
• R is going to Dehradun but is not a professor.
• T is going to Amritsar and is a manager.
• This leaves Q as the only person who can be the accountant going to Delhi.

Ans: (c)

• To find the work done by each force, we use the formula: Work = Change in Kinetic Energy.
• For the first body (mass = 2 kg, speed = v): Kinetic Energy = 0.5 * 2 * v^2 = v^2.
• For the second body (mass = 6 kg, speed = 2v): Kinetic Energy = 0.5 * 6 * (2v)^2 = 12v^2.
• The ratio of work done by F2 to F1 is: 12v^2 / v^2 = 12:1.

Ans: (c)

• The total distance is divided into three parts, with the first part covered at a speed of 3 m/s.
• The remaining two-thirds of the distance is covered in two equal time intervals at speeds of 4.5 m/s and 7.5 m/s.
• To find the average speed, we need to calculate the total distance and total time taken.
• After calculating, the average speed comes out to be 4.5 m/s, which is the correct answer.

Ans: (c)

• The potential energy (PE) of an object increases with height, while the kinetic energy (KE) decreases as it rises.
• At height h, the ratio of PE to KE is given as 3:4, meaning for every 3 units of potential energy, there are 4 units of kinetic energy.
• To find the height where the ratio of KE to PE is 3:4, we can use the relationship between these energies.
• By analyzing the ratios, we find that this condition is satisfied at the height of 4/3h.

Ans: (a)

Ans: (b)
The endoplasmic reticulum forms a vast network inside the cytoplasm and provides the surface for various biochemical activities.

Ans: (b)
The work done on the ball is equal to its kinetic energy when kicked: Work = (1/2) * m * v²
Where:
m = mass (200 g = 0.2 kg)
v = velocity (8 m/s)
Work = (1/2) * (0.2 kg) * (8 m/s)² = 0.1 * 64 = 6.4 J
Therefore, the correct answer is (b) 6.4 J.

Ans: (a)

• The process of rubbing a glass rod with fur transfers electrons.
• Fur loses electrons, resulting in a positive charge on the fur.
• Glass, on the other hand, gains those electrons, becoming negatively charged.
• This is a classic example of static electricity and how materials can exchange charges through friction.

Ans: (c)

• To find the time interval between the echoes, we first calculate the distance the sound travels to the walls and back.
• The distance to wall P is 80 m, and the distance to wall W is 240 m - 80 m = 160 m.
• The sound travels to wall P and back (80 m * 2 = 160 m) and to wall W and back (160 m * 2 = 320 m).
• The total distance is 160 m + 320 m = 480 m.
• Using the speed of sound (340 m/s), the time taken is distance/speed = 480 m / 340 m/s = 1.41 s.
• The time interval between the first echo (from wall P) and the second echo (from wall W) is the difference in time taken for each echo, which is approximately 0.47 s.

Ans: (a)

• Both statements are true: Uranus does indeed have a unique orbital motion that makes it appear to roll on its side.
• High tilt of the rotational axis: The significant tilt of Uranus's axis is what causes this rolling motion.
• Correct explanation: Statement 2 explains why statement 1 is true, as the tilt directly affects the orbital motion.
• Conclusion: Therefore, both statements are true, and statement 2 correctly explains statement 1.

Ans: (a)

• The gravitational force between two masses depends on their mass and the distance between them.

Ans: (a)

• The initial momentum of the body before hitting the wall is Mu (mass times velocity).
• After bouncing back, the final momentum is -Mu (the direction is reversed).
• The change in momentum is calculated as final momentum minus initial momentum: (-Mu) - (Mu) = -2Mu.
• Thus, the magnitude of the change in momentum is 2Mu.

Ans: (a)

• The pitch of a sound is determined by its frequency. Higher frequencies result in higher pitches, while lower frequencies produce lower pitches.
• Velocity refers to the speed of sound in a medium, but it does not affect the pitch.
• Intensity relates to the loudness of the sound, not its pitch.
• Amplitude affects the volume of the sound, but again, not the pitch.

Ans: (c)

• The question asks which substances do not allow light to pass through them. This means we are looking for opaque or cloudy substances.
• Blood and milk are both opaque, meaning they do not let light through, while brine (saltwater) and soda water are generally transparent.
• Thus, the correct answer is (c) because it includes brine and soda water, which do allow light to pass through.
• So, the substances that do not illuminate the path of light are I (Blood) and III (Milk).

Ans: (a)

• To find the number of moles, we use the formula: moles = mass (g) / molar mass (g/mol).
• For Helium (He): 28 g / 4 g/mol = 7 moles.
• For Sodium (Na): 46 g / 23 g/mol = 2 moles.
• For Calcium (Ca): 60 g / 40 g/mol = 1.5 moles.
• Thus, the order of moles is I > II > III, which means Helium has the most moles, followed by Sodium, and then Calcium.

Ans: (a)
Force = Rate of change of momentum
= (mass/time) x velocity
= (0.03 x 5) x 250 = 37.5 N

Ans: (a)
W = F x s = (mg) x s = 2 x 9.8 x 5 = 98 J

Ans: (a)
The frequency of sound waves remains the same regardless of the medium through which they travel. Therefore, the answer is: (a)

Ans: (c)

• Ozone (O₃) consists of three oxygen atoms per molecule.
• Calculating the total number of atoms involves multiplying the number of moles by the number of atoms in each molecule.
• For 0.4 mol of ozone: 0.4 mol x 3 atoms = 1.2 mol of atoms.
• In comparison, the other options yield fewer total atoms: 0.3 mol of nitrogen (0.6 mol), 0.5 mol of oxygen (1 mol), and 0.2 mol of carbon dioxide (0.4 mol).
• Thus, 0.4 mol of ozone gas contains the greatest number of atoms.

Ans: (a)
The common cold is caused by a virus. Kala-azar is caused by a protozoan, anthrax is caused by a bacterium and elephantiasis is caused by a nematode.

Ans: (a)
Force = Mg = 2 x 9.8 = 19.6 N

Ans: (c)

• Element P has its electrons in the L shell, which means it is in the second period of the periodic table, while element Q has its electrons in the M shell, placing it in the third period.
• The atomic number of an element is determined by the number of protons, which corresponds to the number of electrons in a neutral atom.
• For element P, having 5 electrons in the L shell indicates an atomic number of 7 (as it has 2 in the K shell and 5 in the L shell).
• Element Q, with 5 electrons in the M shell, has an atomic number of 15, as it has 2 in the K shell, 8 in the L shell, and 5 in the M shell.

Ans: (d)

• Burning of LPG in kitchen stove is an example of rapid combustion because it occurs quickly and produces heat and light.
• Burning of white phosphorus is classified as spontaneous combustion since it ignites on its own at room temperature.
• Burning of coal dust in coal mines can also lead to spontaneous combustion due to the heat generated from oxidation.
• However, burning of magnesium is not slow combustion; it burns rapidly and produces a bright flame, making option (d) the incorrect match.

Ans: (a)

• Rabi crops 
• Kharif crops 
• In option (a), Pea is a rabi crop and Soybean is a kharif crop, making this pairing correct.
• The other options do not correctly match one rabi and one kharif crop.

Ans: (d)
NPK is chemical fertiliser. Chemical fertilisers tend to cause water pollution and reduces soil fertility and texture.

Ans: (c)

• Ex situ conservation refers to methods like zoological parks and botanical gardens, which are outside the natural habitat.
• The core zone is a protected area in a biosphere reserve where human activities are restricted to preserve biodiversity.
• Reforestation is the process of planting trees in areas where forests have been cut down.
• Mudumalai Sanctuary is located in the state of Tamil Nadu, which is known for its Indian elephants.

Ans: (b)
Power is calculated using the formula: Power = Work / Time
First, we need to calculate the work done against gravity: Work = m * g * h
Where:
m = mass (30 kg)
g = 9.8 m/s²
h = height (15 m)
Work = (30 kg) * (9.8 m/s²) * (15 m) = 4410 J
Now, using the time taken (50 seconds): Power = 4410 J / 50 s = 88.2 W
Thus, the correct answer is (b) 88.2 W.

Ans: (b)
The time interval (T) can be calculated as T = 1 / Frequency = 1 / 40 Hz = 0.025 s.

Ans: (b)

• The correct answer is (b) Cytoplasm, Plasma membrane, Ribosome. These are essential components found in both prokaryotic and eukaryotic cells.
• The cytoplasm is the jelly-like substance where cellular processes occur.
• The plasma membrane surrounds the cell, providing structure and regulating what enters and exits.
• Ribosomes are crucial for protein synthesis and are present in all cell types.

Ans: (d)
Physical, mental and social well-being must be at an ideal level to consider a person as healthy.

Ans: (d)

• Statement 1 is incorrect because parenchyma tissues have thin walls and are not necessarily hard, while collenchyma has thickened cell walls but is still living.
• Statement 2 is also incorrect as parenchyma does not form the hard grit of pears; it is the collenchyma that provides support in young stems and leaves, while the hard walls of nuts are due to sclerenchyma, not collenchyma.
• Thus, both statements are incorrect, making option (d) the right choice.

Ans: (c)
Combustion cannot release nitrogen into the atmosphere

Ans: (d)
According to conservation of linear momentum,
Initial momentum = Final momentum
200 x 0 = 150 x 12 – 50 x v
⇒ v = 36 m/s

Ans: (c)

• Cleft palate is indeed influenced by environmental factors, such as maternal health and nutrition during pregnancy.
• Haemophilia, on the other hand, is a genetic disorder caused by a mutation in genes responsible for blood clotting.
• Options (a) and (b) are incorrect because acute diseases are typically short-term, and acquired diseases are not present at birth.
• Option (d) is also incorrect as both AIDS and German measles can be transmitted from an infected mother to her baby.

Ans: (d)
Bryophytes establish over rocks just after lichens and their roots help to whether the rocks over time.
The wind picks up rocks and smashes them against each other and produces soil.
Water on the other hand may freeze during the night in the crevices and causes breakage of rocks.

Ans: (d)

• Soil L has good aeration but lacks water retention, making it less ideal for plants.
• Soil M is well aerated and retains water effectively, making it the best choice for plant growth.
• Soil N holds a lot of water but is poorly aerated, which is not suitable for most plants.
• Thus, the statement that Soil L and N are not suitable for plant growth while Soil M is best suited is correct.

Ans: (b)
Ribosomes are seen in both prokaryotes and eukaryotes. But they are structurally different. However, ribosomes that are similar to the ones in prokaryotes can be seen inside both mitochondria and plastids.

Ans: (d)
Peptic ulcer is caused by the bacteria named Helicobacter and is mostly found in the upper gastrointestinal tract.  

Ans: (c)
A pure substance consists of a single type of particles having the same chemical nature.
Elements like iron, and compounds like hydrochloric acid and calcium oxide are all pure substances.
Milk, however, is a mixture of several substances, such as water, sugar, fat, protein etc. It is an impure substance because the constituent particles are chemically different.

Ans: (a)
When a speeding car takes a sharp turn, the centripetal force helps keep the car in its curved track. The part of passenger's body that is in contact with the car will be in its position due to frictional force.
The rest of the body of the passengers will experience a centrifugal force which is directed away from the center of the curved path.
So the passengers tend to fall sideways when a speeding car takes a sharp turn.

Ans: (a)
Meristem is a region of plant tissue, found chiefly at the growing tips of roots and shoots and in the cambium, consisting of actively dividing cells forming new tissue. Apical meristem is found at the apices of the stem, root and their branches