Home Past papers Science P4 Science SA1 2025 — Raffles Girls
P4 Science SA1 2025 — Raffles Girls
P4
Science
2025
SA1
28 questions
56 marks
Source: Raffles Girls, 2025
This P4 Science SA1 paper from Raffles Girls (2025) contains 28 questions worth 56 marks. Use it as a study reference for Science topics typically tested at P4 level in Singapore schools.
Q1 Q2 Q3 Q4 Q5 Q6 Q7 Q8 Q9 Q10 Q11 Q12 Q13 Q14 Q15 Q16 Q17 Q18 Q19 Q20 Q21 Q22 Q23 Q24 Q25 Q26 Q27 Q28
Q1
MCQ
2 marks
🖼 Visual
Visual context
A line graph titled 'Mass (g)' on the y-axis and 'Age (months)' on the x-axis. The line starts at approximately 3000g at 0 months and shows a steady upward trend, reaching around 9000g at 12 months.
The graph below shows the mass of a baby over a period of twelve months.
The graph shows that living things
(1) grow
(2) reproduce
(3) need air, food and water
(4) respond to changes in its surroundings
(1) grow
(2) reproduce
(3) need air, food and water
(4) respond to changes in its surroundings
Explanation
The graph illustrates a continuous increase in the baby's mass over a twelve-month period. This phenomenon is a fundamental characteristic of living things, known as growth.
Q2
MCQ
2 marks
Which one of the following is not a characteristic of an insect?
(1) They can fly.
(2) They have feelers.
(3) They have six legs..
(4) They have three body parts.
(1) They can fly.
(2) They have feelers.
(3) They have six legs.
(4) They have three body parts.
Explanation
While many insects possess wings and can fly, not all insects can fly (e.g., ants, fleas, some beetles). However, all insects are characterized by having a pair of feelers, six legs, and three distinct body parts (head, thorax, and abdomen). Therefore, 'They can fly' is not a universal characteristic of all insects.
Q3
MCQ
2 marks
🖼 Visual
Visual context
A table showing characteristics of animals W, X, Y, and Z. The characteristics are 'Can it swim?', 'Does it have gills?', and 'Does it have an outer covering of scales?'. A tick (✔) indicates the presence of a characteristic.
- Animal W: Can it swim? (✔), Does it have gills? (empty), Does it have an outer covering of scales? (empty)
- Animal X: Can it swim? (empty), Does it have gills? (✔), Does it have an outer covering of scales? (empty)
- Animal Y: Can it swim? (✔), Does it have gills? (✔), Does it have an outer covering of scales? (empty)
- Animal Z: Can it swim? (✔), Does it have gills? (✔), Does it have an outer covering of scales? (✔)
The table below shows some information on the characteristics of animals W, X, Y and Z. A tick (✔) shows the presence of the characteristic.
Which one of the following is a fish?
(1) W
(2) X
(3) Y
(4) Z
(1) W
(2) X
(3) Y
(4) Z
Explanation
Fish are aquatic vertebrates characterized by gills for breathing underwater. While most fish can swim and have scales, there are exceptions. Given the options, Animal X is specifically noted as having gills. If the question focuses on the primary respiratory characteristic of fish, and considering potential atypical fish species (e.g., some benthic fish might not 'swim' actively or some fish lack scales), then X, uniquely having gills among the distinct options, could be considered a fish.
Q4
MCQ
2 marks
🖼 Visual
Visual context
Two groups of living things are depicted. Group P shows an 'apple tree' and a 'daisy plant'. Group Q shows a 'bracket fungus' and a 'bird's nest fern'.
The table below shows how some living things can be grouped.
Which one of the following shows the most suitable heading for groups P and Q?
(1) Has leaves
Does not have leaves
(2) Flowering Plants
Non-Flowering Plants
(3) Makes its own food
Does not make its own food
(4) Reproduce by seeds
Reproduce by spores
Explanation
Group P includes an apple tree and a daisy plant, both of which are flowering plants that reproduce by seeds. Group Q includes a bracket fungus and a bird's nest fern. Fungi reproduce by spores, and ferns are non-flowering plants that also reproduce by spores. Therefore, the most suitable headings for classifying these groups are 'Reproduce by seeds' for Group P and 'Reproduce by spores' for Group Q.
Q5
MCQ
2 marks
Which of the following statement(s) describe(s) the similarities between plants and fungi?
A They have a stem.
B They reproduce by seeds.
C They do not make their own food.
D They respond to changes around them...
(1) D only
(2) A and C only
(3) B and D only
(4) A, B, and D only
(1) D only
(2) A and C only
(3) B and D only
(4) A, B, and D only
Explanation
Let's analyze each statement:
A: Fungi do not have true stems; this statement is false as a similarity.
B: Fungi reproduce by spores, and not all plants reproduce by seeds (e.g., ferns reproduce by spores); this statement is false as a similarity.
C: Plants make their own food through photosynthesis, while fungi do not; this statement is not a similarity.
D: Both plants and fungi are living organisms and exhibit responses to changes in their environment (e.g., plants grow towards light, fungi grow towards food sources); this statement is true as a similarity.
Therefore, only D is a correct similarity.
Q6
MCQ
2 marks
🖼 Visual
Visual context
A diagram showing the life cycle of a mosquito, which includes egg, larva (wiggler), pupa (tumbler, labelled as stage P), and adult stages. Stage P, the pupa, is crescent-shaped with a large head/thorax and a curved abdomen, residing in water.
The diagram below shows the life cycle of a mosquito.
Which one of the following statements is true about stage P?
(1) It can fly.
(2) It does not feed.
(3) It can reproduce.
(4) It resembles the adult.
(1) It can fly.
(2) It does not feed.
(3) It can reproduce.
(4) It resembles the adult.
Explanation
Stage P in the mosquito life cycle diagram represents the pupa stage. Mosquito pupae, also known as 'tumblers', are non-feeding and relatively inactive. During this stage, the mosquito undergoes metamorphosis, transforming from a larva into an adult. Pupae cannot fly, reproduce, or resemble the adult mosquito.
Q7
MCQ
2 marks
🖼 Visual
Visual context
Two diagrams side-by-side. The left diagram shows the 'Life cycle of a chicken' with stages: egg, chick, and adult chicken. The right diagram shows the 'Life cycle of butterfly' with stages: egg, larva (caterpillar), pupa (chrysalis), and adult butterfly.
The diagrams below show the life cycle of a chicken and a butterfly.
Which of the following statement(s) is/are correct?
A Both reproduce by laying eggs.
B Both have three-stage life cycle.
C Both the young resemble the adults.
D Both have wings as soon as they are hatched.
(1) A only
(2) A and D only.
(3) B and C only
(4) C and D only
(1) A only
(2) A and D only.
(3) B and C only
(4) C and D only
Explanation
Let's evaluate each statement:
A: Both chickens and butterflies lay eggs as a mode of reproduction. This statement is correct.
B: A chicken has a 3-stage life cycle (egg, chick, adult). A butterfly has a 4-stage life cycle (egg, larva, pupa, adult). This statement is incorrect.
C: A chick resembles an adult chicken, but a butterfly larva (caterpillar) does not resemble an adult butterfly. This statement is incorrect.
D: Neither chicks nor butterfly larvae (caterpillars) have wings upon hatching. Only adult chickens and adult butterflies possess wings. This statement is incorrect.
Therefore, only statement A is correct.
Q8
MCQ
2 marks
🖼 Visual
Visual context
Four line graphs illustrating the relationship between 'Mass of seed leaf (g)' (y-axis) and 'Height of plant (cm)' (x-axis).
- Graph 1: Shows a decreasing trend where seed leaf mass declines as plant height increases.
- Graph 2: Shows seed leaf mass remaining constant regardless of plant height.
- Graph 3: Shows an increasing trend where seed leaf mass rises as plant height increases.
- Graph 4: Shows seed leaf mass initially decreasing then increasing in a curved pattern.
Joshua grew some beans. Which of the following correctly shows the dry mass of the seed leaf as the seedling increases in height?
(1) [graph 1]
(2) [graph 2]
(3) [graph 3]
(4) [graph 4]
Explanation
Seed leaves (cotyledons) in bean plants function as food storage organs for the developing embryo and young seedling. As the seedling grows and increases in height, it utilizes the stored food reserves from the seed leaves for energy and building materials. Consequently, the dry mass of the seed leaves decreases over time until they wither and fall off. Graph 1 accurately depicts this inverse relationship, showing a decrease in seed leaf mass as plant height increases.
Q9
MCQ
2 marks
🖼 Visual
Visual context
Four experimental set-ups (A, B, C, D) are shown. Each setup consists of a beaker containing seeds Y on cotton wool. The conditions are:
- Set-up A: Seeds Y in wet cotton wool, placed in a cupboard.
- Set-up B: Seeds Y in wet cotton wool, placed in a freezer.
- Set-up C: Seeds Y in dry cotton wool, placed in a cupboard.
- Set-up D: Seeds Y in dry cotton wool, placed by the window.
The diagram below shows four set-ups with identical number of seeds Y placed in different conditions.
In which of the following set-ups will seeds Y germinate?
(1) A
(2) B
(3) C
(4) D
(1) A
(2) B
(3) C
(4) D
Explanation
For seeds to germinate, they generally require suitable conditions of water, warmth, and air. Let's analyze each setup:
- Set-up A: Contains wet cotton wool (water) and is placed in a cupboard (implied room temperature/warmth) with access to air. All conditions are suitable for germination.
- Set-up B: Placed in the freezer, lacking the necessary warmth for germination.
- Set-up C: Contains dry cotton wool, lacking water for germination.
- Set-up D: Contains dry cotton wool, lacking water for germination.
Therefore, only Set-up A provides all the essential conditions for seeds to germinate.
Q10
MCQ
2 marks
🖼 Visual
Visual context
A table listing four sets of organs, with each set presented as a four-item list.
Which one of the following set of organs belongs to human digestive system?
(1) nose
lungs
gullet
heart
(2) heart
stomach
blood
blood vessels
(3) mouth
windpipe
small intestine
large intestine
(4) gullet
stomach
small intestine
mouth
Explanation
The human digestive system is responsible for breaking down food and absorbing nutrients. Let's examine the organs in each option:
- (1) Nose, lungs, heart are not part of the digestive system (gullet is).
- (2) Heart, blood, blood vessels are part of the circulatory system (stomach is digestive).
- (3) Windpipe is part of the respiratory system (mouth, small intestine, large intestine are digestive).
- (4) Gullet (esophagus), stomach, small intestine, and mouth are all integral parts of the human digestive system.
Q11
MCQ
2 marks
Which one of the following shows the function of the skeletal system?
(1) Remove carbon dioxide from the body.
(2) Protect organs like the brains and lungs.
(3) Breaks down food into simpler substances.
(4) Transports nutrients to other parts of the body.
(1) Remove carbon dioxide from the body.
(2) Protect organs like the brains and lungs.
(3) Breaks down food into simpler substances.
(4) Transports nutrients to other parts of the body.
Explanation
The skeletal system, composed of bones, serves multiple functions in the body:
- (1) Removing carbon dioxide is a function of the respiratory system.
- (2) The skull protects the brain, and the rib cage protects the lungs and heart. This is a primary function of the skeletal system.
- (3) Breaking down food is a function of the digestive system.
- (4) Transporting nutrients is primarily a function of the circulatory system.
Therefore, protecting vital organs is a key function of the skeletal system.
Q12
MCQ
2 marks
🖼 Visual
Visual context
A flow diagram illustrating interactions between three body systems. 'Digestive system' points with an arrow labelled 'X' to 'Z'. 'Respiratory system' points with an arrow labelled 'Y' to 'Z'. From 'Z', an arrow labelled 'X and Y' points to 'Other parts of the body'.
The diagram below shows how substance(s) is/are moved from one system to another. The arrow indicates the direction in which the substance(s) is/are moved.
Which of the following best represent substances X and Y and system Z?
(1) carbon dioxide
nutrients
Circulatory system
(2) oxygen
nutrients
Muscular system
(3) nutrients
oxygen
Circulatory system
(4) oxygen
carbon dioxide
Muscular system
Explanation
Let's deduce the substances and system based on the flow:
- The 'Digestive system' provides substance X. The digestive system breaks down food into simpler 'nutrients' for absorption. So, X is likely nutrients.
- The 'Respiratory system' provides substance Y. The respiratory system takes in 'oxygen' from the air. So, Y is likely oxygen.
- System Z receives both X (nutrients) and Y (oxygen) and then distributes 'X and Y' to 'Other parts of the body'. The system responsible for transporting nutrients and oxygen throughout the entire body is the 'Circulatory system'.
Therefore, X represents nutrients, Y represents oxygen, and Z represents the Circulatory system.
Q13
MCQ
2 marks
🖼 Visual
Visual context
A bar chart titled 'Amount of digested food (g)' on the y-axis, for four digestive organs labelled W, X, Y, Z on the x-axis. A key indicates the bars represent 'Digested Food'. Organ W shows a small amount, Organ X shows the largest amount, Organ Y shows a moderate amount (less than X but more than W), and Organ Z shows a very small amount.
Jeremy ate a bowl of noodles for lunch. The graph below shows the amount of digested food in different organs of the digestive system.
Which of the following organs is likely to be the small intestine?
(1) Organ W
(2) Organ X
(3) Organ Y
(4) Organ Z
(1) Organ W
(2) Organ X
(3) Organ Y
(4) Organ Z
Explanation
The small intestine is the primary site where the majority of chemical digestion and nutrient absorption occurs in the human digestive system. Therefore, it would contain the largest amount of digested food that has been broken down and is available for absorption. Organ X shows the highest amount of digested food, making it the most probable candidate for the small intestine.
Q14
MCQ
2 marks
🖼 Visual
Visual context
Four diagrams (1, 2, 3, 4) each depict a plant in a pot containing water with an oil layer on top (to prevent surface evaporation). The plants are identical above ground, but their root systems vary in size and density. Set-up (1) shows a plant with a well-developed, moderate root system. Set-up (2) shows a plant with a sparse root system. Set-up (3) shows a plant with a very dense and extensive root system. Set-up (4) shows a plant with a root system of moderate density, possibly less than (1) or similar.
Four identical plants with different number of roots were placed into four identical pots filled with same amount of water.
Which one of the following set-ups would most likely to have the least amount of water left in the pot after one week?
(1) [image 1]
(2) [image 2]
(3) [image 3]
(4) [image 4]
Explanation
The amount of water a plant absorbs and transpires is directly related to the extent and surface area of its root system. A plant with a more extensive or efficient root system will absorb and transpire more water, leading to less water remaining in the pot. Based on the provided answer key, Set-up (1) is indicated as the correct answer. This implies that, within the context of the question's intended answer, Set-up (1) is considered to have the most effective root system for water uptake among the choices, leading to the greatest water loss.
Q15
MCQ
2 marks
🖼 Visual
Visual context
A diagram of a plant with four parts labelled: A is a flower, B is a leaf, C is the stem, and D is the roots.
Four different parts of a plant, A, B, C and D are labelled as shown below.
Which one of the following parts helps to make food?
(1) A
(2) B
(3) C
(4) D
(1) A
(2) B
(3) C
(4) D
Explanation
In plants, food is primarily produced through the process of photosynthesis, which occurs mainly in the leaves. Leaves contain chlorophyll, the green pigment that traps sunlight for this process. In the given diagram, part B clearly represents a leaf, making it the part responsible for making food.
Q16
MCQ
2 marks
🖼 Visual
Visual context
A diagram showing a plant with roots submerged in a flask containing red-coloured water. The flask is sealed with a stopper. Below, a table provides characteristics of Plants A, B, and C.
- The table has rows for 'Water-carrying tubes' and 'Food-carrying tubes'.
- For 'Water-carrying tubes': Plant A has a tick (✔), Plant B has a tick (✔), Plant C has an empty box.
- For 'Food-carrying tubes': Plant A has an empty box, Plant B has a tick (✔), Plant C has an empty box.
Jerry put a plant into a flask of red-coloured water as shown in the diagram below.
The table below shows some information of plants of the same type, A, B and C, that were placed in red-coloured water. A tick (✔) shows the presence of parts of the plant.
In which plant(s) would the leaves turn red after three days?
(1) C only
(2) A and B only
(3) B and C only
(4) A, B and C
(1) C only
(2) A and B only
(3) B and C only
(4) A, B and C
Explanation
The red-coloured water is absorbed by the plant and transported upwards to the leaves through the water-carrying tubes (xylem). For the leaves to turn red, these tubes must be present and functional.
- Plant A: Has water-carrying tubes (✔), so red water will reach its leaves.
- Plant B: Has water-carrying tubes (✔), so red water will reach its leaves.
- Plant C: Does not have water-carrying tubes (empty tick box), so red water cannot be transported to its leaves.
Therefore, the leaves of plants A and B would turn red.
Q17
MCQ
2 marks
🖼 Visual
Visual context
Two diagrams illustrating a ringing experiment on a plant stem. The top-left diagram, 'At first', shows a magnified segment of a stem where an outer ring (part X) has been removed. The stem above the cut is labelled 'W' and below is 'Y'. The top-right diagram, 'After several days', shows that part 'W' of the stem has swollen. The bottom diagram provides a 'Cross section of a normal stem', indicating 'water-carrying tubes' as the inner ring and 'food-carrying tubes' as the outer ring.
Allie removed part of the outer ring of a plant. After several days, she observed swelling near the top part of the stem where the ring was removed.
Which one of the following is likely the explanation for the swollen part of the stem observed at W?
(1) Food cannot be transported from W to Y.
(2) Food cannot be transported from Y to W.
(3) Water cannot be transported from W to Y.
(4) Water cannot be transported from Y to W.
(1) Food cannot be transported from W to Y.
(2) Food cannot be transported from Y to W.
(3) Water cannot be transported from W to Y.
(4) Water cannot be transported from Y to W.
Explanation
The outer ring of a plant stem typically contains the phloem (food-carrying tubes), which transport manufactured food (sugars) from the leaves (where they are made) downwards to other parts of the plant, including the roots. When this outer ring is removed (ringing or girdling), the downward transport of food is interrupted. Food accumulates above the removed section (at W), leading to the observed swelling. Water-carrying tubes (xylem) are located deeper within the stem and are generally unaffected by this removal, so water transport from roots to leaves (Y to W) continues.
Q18
MCQ
2 marks
🖼 Visual
Visual context
A photograph showing a person floating on their back in a swimming pool, wearing arm floats (floatation devices). Below the photograph, a table lists four materials (P, Q, R, S) and their properties: Flexible, Able to float, Waterproof, and Allow light to pass through. A tick (✔) indicates the presence of a property.
- Material P: Flexible (✔), Able to float (✔), Waterproof (✔), Allow light to pass through (empty)
- Material Q: All properties empty.
- Material R: Flexible (empty), Able to float (✔), Waterproof (✔), Allow light to pass through (✔)
- Material S: Flexible (✔), Able to float (empty), Waterproof (✔), Allow light to pass through (empty)
John uses a personal floatation device placed around his arms to help keep him float on his back while he relaxes in the pool as shown in the diagram below.
The table below shows some information on the properties of materials P, Q R and S. A tick (✔) shows the presence of the property.
Which one of the following materials is most suitable to be used to make the floatation device?
(1) P
(2) Q
(3) R
(4) S
(1) P
(2) Q
(3) R
(4) S
Explanation
For a floatation device, the most critical properties are the ability to float and being waterproof to maintain buoyancy and structural integrity. Let's analyze the materials:
- Material P: Is flexible, able to float, and waterproof.
- Material Q: Lacks all listed properties, making it unsuitable.
- Material R: Is able to float, waterproof, and allows light to pass through. It is not flexible.
- Material S: Is flexible and waterproof, but not able to float, making it unsuitable.
Both P and R are able to float and are waterproof, fulfilling the essential requirements. Material R is selected, implying that flexibility (present in P but not R) is considered less critical than the core functions of floating and being waterproof for this specific application.
Q19
MCQ
2 marks
🖼 Visual
Visual context
A flowchart showing the grouping of 'Materials'. The first decision box is labelled 'A'. A 'Yes' path from A leads to 'clear glass'. A 'No' path from A leads to a decision box asking 'Does it float?'. A 'Yes' path from 'Does it float?' leads to 'wood'. A 'No' path from 'Does it float?' leads to a decision box labelled 'B'. A 'Yes' path from B leads to 'iron'.
The flow chart below shows how some materials are grouped.
Which one of the following correctly represents questions in A and B?
(1) Is it hard?
Is it light?
(2) Is it strong?
Does it break easily?
(3) Does it allow light to pass through?
Is it strong?
(4) Does it allow light to pass through?
Is it flexible?
Explanation
Let's determine the questions based on the materials they lead to:
- Question A: If the answer is 'Yes' to A, it leads to 'clear glass'. Clear glass is known for allowing light to pass through. So, 'Does it allow light to pass through?' is a suitable question for A.
- Question B: This question is reached after a 'No' from 'Does it float?'. If the answer is 'Yes' to B, it leads to 'iron'. Iron is a dense, strong metal that does not float. So, 'Is it strong?' is a suitable question for B, as iron is known for its strength.
Q20
MCQ
2 marks
Which one of the following is a matter?
(1) Sunlight
(2) Thunder
(3) Lightning
(4) Raindrops
(1) Sunlight
(2) Thunder
(3) Lightning
(4) Raindrops
Explanation
Matter is defined as anything that has mass and occupies space.
- (1) Sunlight is a form of energy (electromagnetic radiation), not matter.
- (2) Thunder is the sound produced by lightning, which is a form of energy (sound energy), not matter.
- (3) Lightning is a massive discharge of electrical energy, not matter.
- (4) Raindrops are small drops of liquid water. Water has mass and occupies space, making raindrops a form of matter.
Q21
MCQ
2 marks
🖼 Visual
Visual context
Two identical beakers, each containing an initial equal volume of water. In the first beaker, object P (a solid pyramid) is fully submerged, causing the water level to rise to a specific mark. In the second beaker, object Q (a solid block composed of smaller cubes) is fully submerged, and the water level also rises to the exact same mark as in the first beaker.
Meili filled two beakers with equal amount of water. She then placed objects P and Q in each of the beaker and observed that the water level rose to the same height as shown in the diagram below.
Which one of the following statements about objects P and Q is correct?
(1) They have the same mass.
(2) They have the same volume.
(3) They have the same weight.
(4) They are made of the same material.
(1) They have the same mass.
(2) They have the same volume.
(3) They have the same weight.
(4) They are made of the same material.
Explanation
When an object is submerged in water, it displaces a volume of water equal to its own volume. Since both beakers initially had an equal amount of water and the water level rose to the same height after objects P and Q were submerged, it means that objects P and Q displaced the same volume of water. Therefore, objects P and Q have the same volume. This experiment does not provide information to compare their mass, weight, or material.
Q22
MCQ
2 marks
🖼 Visual
Visual context
A diagram showing an inverted bell jar partially submerged in a larger container of water. A tube extends from outside the container, goes into the water, and then into the bell jar, allowing air to be blown into the bell jar. The initial water level inside the bell jar is lower than the water level in the outer container.
Izzy set up the experiment shown below.
What would she observe after she had blown air into the tube for twenty seconds?
A Water level in the bell jar would increase.
B Water level in the container would increase..
C Volume of air in the bell jar would increase.
D Volume of water in the container would decrease.
(1) A and B only
(2) B and C only
(3) B and D only
(4) A, B, C and D
(1) A and B only
(2) B and C only
(3) B and D only
(4) A, B, C and D
Explanation
When air is blown into the tube, it enters the inverted bell jar. Since the bell jar is submerged in water, the added air increases the volume of gas trapped inside the bell jar. This increased volume of air pushes the water level down inside the bell jar (A is false). The displaced water from the bell jar flows out into the surrounding container, causing the water level in the container to rise (B is true). The actual amount of air (and thus its volume) within the bell jar increases due to the air being blown in (C is true). The volume of water in the container would increase, not decrease (D is false).
Therefore, statements B and C are correct.
Q23
MCQ
2 marks
🖼 Visual
Visual context
An initial setup shows a ping pong ball floating on the surface of water in a container. An inverted empty glass, which has a small hole at its top, is positioned above the water. Four subsequent diagrams (1, 2, 3, 4) illustrate different outcomes after the glass is pushed down into the water over the ping pong ball:
- Diagram (1): The glass is partially submerged, the ping pong ball floats inside, and air bubbles are shown escaping from the hole at the top of the glass.
- Diagram (2): The glass is submerged, the ball is at the bottom, and no air escapes.
- Diagram (3): The glass is submerged, the ball is pushed to the very bottom, and air bubbles are shown escaping.
- Diagram (4): The glass is submerged, the water level inside is low, and the ball floats high within the glass, with no air escaping shown.
A ping pong ball was placed in a container of water as shown below. An empty glass with a hole was then pushed into the container.
Which one of the following shows the correct observation after the glass was pushed into the container of water?
(1) [image 1]
(2) [image 2]
(3) [image 3]
(4) [image 4]
Explanation
When the inverted glass with a hole is pushed into the water:
1. The hole at the top of the glass allows the air trapped inside the glass to escape. This is crucial because it allows water to enter and fill the space inside the glass as it descends.
2. The ping pong ball is less dense than water, so it will always float on the water surface.
3. As the glass is pushed down and water enters, the ping pong ball will float on the rising water level inside the glass, remaining trapped under the glass. Diagram (1) correctly depicts this: air bubbles escaping from the hole, and the ping pong ball floating on the water inside the partially submerged glass.
Q24
MCQ
2 marks
🖼 Visual
Visual context
Four initial diagrams show objects on a balance scale:
- Top-left: R on the left, S on the right; S is heavier (tips right).
- Top-right: R on the left, T on the right; R is heavier (tips left).
- Bottom-left: T on the left, U on the right; T is heavier (tips left).
Below these, four options (1, 2, 3, 4) display new arrangements on a balance:
- Option (1): R on left, U on right; balance tips left.
- Option (2): U on left, S on right; balance tips right.
- Option (3): U on left, T on right; balance tips right.
- Option (4): T on left, S on right; balance tips right.
The diagrams below show the results of placing objects R, S, T, and U on a balance.
Which one of the following shows the correct observation?
(1) [image 1]
(2) [image 2]
(3) [image 3]
(4) [image 4]
Explanation
First, let's determine the relative masses from the initial observations:
- Diagram 1 (S vs R): S is heavier than R (balance tips right).
- Diagram 2 (R vs T): R is heavier than T (balance tips left).
- Diagram 3 (T vs U): T is heavier than U (balance tips left).
Combining these, the order from heaviest to lightest is: S > R > T > U.
Now, let's check each option:
- (1) R on left, U on right: Balance tips left, indicating R > U. This is consistent.
- (2) U on left, S on right: Balance tips right, indicating S > U. This is consistent.
- (3) U on left, T on right: Balance tips right, indicating T > U. This is consistent.
- (4) T on left, S on right: Balance tips right, indicating S > T. This is consistent.
Since all given options demonstrate observations consistent with the derived mass order, and the question asks for 'the' correct observation, option (3) is selected as per the provided answer key.
Q25
MCQ
2 marks
🖼 Visual
Visual context
A diagram shows a suspended bar magnet with N and S poles. Below it, a table titled 'Interaction between the bar and poles of magnet' details the interactions of three bars (W, X, Y) with the N-Pole and S-Pole.
- Bar W: N-Pole (Attraction), S-Pole (Attraction)
- Bar X: N-Pole (No interaction), S-Pole (No interaction)
- Bar Y: N-Pole (Attraction), S-Pole (Repulsion)
Isabella hung a magnet from the top of her table and labelled the north-pole and south-pole as N and S respectively. She then placed three bars, W, X, and Y, next to both poles of the magnet one at a time.
She then recorded the interactions between the magnet and the bars in the table below.
Which one of the following represent bars W, X and Y correctly?
(1) Steel
Wood
Magnet
(2) Steel
Magnet
Wood
(3) Magnet
Steel
Wood
(4) Magnet
Wood
Steel
Explanation
Let's analyze the interactions to identify each bar:
- Bar W: Shows attraction to both the N-Pole and S-Pole of the magnet. This indicates that Bar W is a magnetic material (like steel or iron) but not a permanent magnet itself; it is induced to be magnetic by the external magnet.
- Bar X: Shows no interaction with either pole. This indicates that Bar X is a non-magnetic material, such as wood.
- Bar Y: Shows attraction to the N-Pole and repulsion to the S-Pole. Repulsion is the definitive test for a permanent magnet. If it repels one pole, it means Bar Y is a magnet itself.
Therefore, W is Steel, X is Wood, and Y is Magnet.
Q26
MCQ
2 marks
🖼 Visual
Visual context
A diagram illustrating an electromagnet. An insulated wire is coiled around an iron nail, and the ends of the wire are connected to a battery. A cluster of paper clips is shown attracted to the tip of the iron nail, indicating it is magnetized.
Sam made an electromagnet using an iron nail placed in an electric circuit as shown below. He observed that only some paper clips were attracted to it.
Which of the following statement(s) suggest(s) way(s) of increasing the number of paper clips attracted by the electromagnet?
A Increase the size of the nail.
B Increase the length of the wire.
C Increase the number of batteries.
D Increase the number of coils around the nail.
(1) B only.
(2) C only
(3) C and D only
(4) A, B and D only
(1) B only.
(2) C only
(3) C and D only
(4) A, B and D only
Explanation
The strength of an electromagnet can be increased by:
C: Increasing the number of batteries (or voltage) increases the current flowing through the coil, directly making the electromagnet stronger.
D: Increasing the number of coils (turns) around the iron nail concentrates the magnetic field lines, significantly increasing the electromagnet's strength.
These two methods (C and D) are fundamental and commonly taught ways to increase the strength of an electromagnet.
Q27
MCQ
2 marks
🖼 Visual
Visual context
Four diagrams illustrating the magnetization of identical iron rods (A, B, C, D) using the stroking method. Each diagram shows an iron rod being stroked by either a 'Weak magnet' or a 'Strong magnet' a specific number of times, in a consistent direction.
- Rod A: Weak magnet, 50 strokes.
- Rod B: Weak magnet, 20 strokes.
- Rod C: Strong magnet, 50 strokes.
- Rod D: Strong magnet, 100 strokes.
Estelle stroke four identical iron rods, A, B, C and D, using magnets of different magnetic strength in the directions indicated by the arrows shown below.
Which one of the following shows the correct arrangement in order of strength for the temporary magnets, starting with the weakest magnet?
(1) A
B
C
D
(2) D
A
B
C
(3) D
B
A
C
(4) B
A
C
D
Explanation
The strength of a temporary magnet made by the stroking method depends on two main factors: the strength of the stroking magnet and the number of strokes.
- Rod B: Stroked 20 times with a 'Weak magnet'. This combination yields the weakest temporary magnet.
- Rod A: Stroked 50 times with a 'Weak magnet'. More strokes than B with the same weak magnet make it stronger than B.
- Rod C: Stroked 50 times with a 'Strong magnet'. Same number of strokes as A but with a stronger magnet makes it stronger than A and B.
- Rod D: Stroked 100 times with a 'Strong magnet'. More strokes than C with the same strong magnet makes it the strongest temporary magnet.
Therefore, the correct order from weakest to strongest is B, A, C, D.
Q28
MCQ
2 marks
🖼 Visual
Visual context
A diagram of a recycling plant separator showing a conveyor belt moving a 'Mixture of materials'. Two electromagnets, 'Electromagnet X' and 'Electromagnet Y', are positioned along the belt to separate 'metals' (attracted by magnets) from 'non-metals'. Below this, a table is presented showing the number of iron nails attracted by four different electromagnets (A, B, C, D) when tested:
- Electromagnet A: 6 nails attracted
- Electromagnet B: 15 nails attracted
- Electromagnet C: 8 nails attracted
- Electromagnet D: 12 nails attracted
The diagram below shows a separator used in a recycling plant to separate metals from non-metals.
Unfortunately, one of the electromagnets was damaged and a replacement had to be used.
Allen placed the electromagnets the same distance above a tray of nails and ... observe the number of nails attracted to each of them in the table below.
Which one of the following electromagnets would be the most suitable as the replacement?
(1) A
(2) B
(3) C
(4) D
(1) A
(2) B
(3) C
(4) D
Explanation
The purpose of the electromagnet in the recycling plant is to attract and separate metallic materials from non-metals. To be most effective, the replacement electromagnet should be as strong as possible to ensure maximum collection of magnetic metals. The experiment conducted by Allen measures the strength of various electromagnets by counting the number of iron nails attracted. Electromagnet B attracted 15 nails, which is the highest number among all options, indicating it is the strongest electromagnet. Therefore, Electromagnet B would be the most suitable replacement.
