In this article, we will be analysing the 2017 PSLE Science Exam Paper. We will be sharing the topic weightage for 2017 PSLE paper as well as discussing 2 interesting questions from the booklet B of this paper.

Table 1: Summary of Booklet A Analysis

Table 2: Summary of Booklet B Analysis

We have also identified the top 10 topics in 2017 PSLE Science Exam Paper and most of the topics are taught in Upper Primary (Cycles and Interactions). Hence it is very important that your child has a firm grasp of the concepts of these topics. Reproduction in plants has the highest weightage in the paper with 11 marks in total. This is an important topic in Primary 5 and requires the student to remember a lot of content about the plant reproduction processes. Reproduction in plants has been appearing as a highly weighted topic for past 4 years in PSLE. Thus, it is crucial for your child to be well-versed in this topic.

Top 10 topics in 2017 PSLE Science Exam Paper

Other than Reproduction in plants, the other 2 topics that students should pay attention to are Forms and Uses of Energy and Diversity of Living Things. Students tend to neglect revising well for Diversity of Living Things as it is a P3 topic. However, concepts about Diversity are often tested in PSLE.

Table 3: Top 10 topics in 2017 PSLE Science Exam Paper

As shown in Table 3, this paper focuses on Reproduction in Plants, Forms and Uses of Energy, Diversity of Living Things and Water and Changes of States. The topic on Electricity is also of high weightage, giving a total of 7 marks (“Using Electricity” and “Electrical System” combined). Hence, this paper is ideal for your child to practise on these topics.

Question Analysis

We would like to discuss the open-ended questions Questions 29 and 32. These 2 questions on “Reproduction in Plants” test students on the definitions of science terms and does not require answering techniques. Furthermore, Question 30 on “Diversity of Living Things” tests student on their ability to analyse table and graphs, which has minimal keywords for us to learn. Hence, we shall discuss Questions 38 and 40, which we can learn the tips and answering techniques that are useful for answering questions on “Forms and Uses of Energy”, “Forces” and “Electricity”, which many students struggle with. For open-ended questions on “Water and Changes of State”, you may want to look at our previous article on 2018 PSLE Science Exam Paper Analysis.

The discussion of the questions below will include 1) the publisher’s answers, 2) explanation of the answers, 3) comments on the answers and 4) tips or answering techniques for the question.

PSLE / 2017 / Q38

Muthu performed an experiment on two different types of springs, P and Q, of the same length using the set-up shown in Diagram 1.

He measured the extension of the spring after adding a mass.

His results are shown in Table 1 below.

(a)    Based on his results, state the relationship between the mass and extension of spring P. [1]

Answer:  As the mass added increases, the extension of the spring increases.

Explanation: As the mass increases, the amount of gravitational force acting on the mass increasing, hence the pull force acting on the spring increases, causing the extension of the spring to increase.

Comments: Students are to analyse the results in the table for “mass” and “extension” to deduce their relationship or know how the mass affects the extension of Spring P. The answer would be more accurate if it can answer to the question: “As the mass added increases, the extension of spring P increases.”

Tips: Students tend to use different answering format for relationship question, which will be penalise in some schools (may/may not in PSLE?). For example, “The greater the mass, the extension of spring P increase.” If students would write “The greater the mass,” then he/she should continue with “the greater the extension of spring P” for this relationship format.

(b)    Explain the purpose of the pin in the set-up. [1]

Answer: he pin helps in taking readings on the ruler accurately.

Explanation: The pin is used to point at the reading on the ruler and can minimize human error.

Comments: This tests students on their ability to rationalise the procedure/set-up of the experiment.

Tips: Students can practise to rationalise steps as they do experiments in their science classes.

Muthu used spring P to make a dish rack as shown in Diagram 2.

 (c)   When Muthu removed a few plates quickly from the top, the metal disc moved up continuously from A to C. Name the main forms of energy of the metal disc at B. [1]

Answer:  Gravitational potential energy and kinetic energy.

Explanation: The metal disc is not fixed in position. The metal disc moved up because the stretched spring P pulled it up. The metal disc gained gravitational potential energy as it moved up. It possesses kinetic energy as it moved.

Comments: PSLE accepts “Potential energy” instead of “Gravitational potential energy” as well. Students tend to confuse “gravitational potential energy” with “gravitational force” and may make careless mistake e.g. writes “gravitational energy”.

Tips: When an object is increasing in height, it can be linked to “gravitational potential energy” while the movement of an object can be linked to “kinetic energy”.

(d) Next, Muthu changed all the spring P to spring Q. He put back all the plates on the metal disc. Based on the results in Table 1, describe one difference Muthu will observe of the new dish rack with spring Q when he removes a plate from the top. Explain your answer. [2]

Answer:  Spring Q extends less than spring P when the same mass is added, so spring Q possesses more elastic potential energy than spring P for the same amount of extension. When Muthu removes a plate from the rock with spring Q, the metal disc will gain more kinetic energy and hence will move faster.

Explanation: Spring Q is less elastic than Spring P hence Spring Q possesses more elastic potential energy than Spring Q.

Comments: This question tests on the energy conversion happening in the springs. Examiners may look out for keywords like “converted to more kinetic energy” and the object at which the energy conversion happens. Hence, a better would be “ When Muthu removes a plate from the rock with spring Q, more elastic potential energy of spring Q is converted to more kinetic energy, transferring more kinetic energy to the metal disc for it to move faster.”

Tips: Students can analyse step by step to derive the final observation of the metal disc moving faster.

PSLE / 2017 / Q40

Poh Lee wants to remove water from the ground using a water pump when it rains heavily. He uses the set-up shown below to turn on the water pump.

Rain water enters the container through a hole at G.

(a) State a property of rubber that allows the set-up to work properly. [1]

Answer: Rubber is a poor conductor of electricity/ an electrical insulator.

Explanation:  Without the rubber, electric current would be able to flow between the metal rods and the metal container.

Comments: Rubber does not conduct electricity hence it should be “non-conductor of electricity” instead of “poor conductor of electricity”.

Tips: Students can identify the topic tested by looking at the electrical circuit in the diagram, and link rubber, which is a material, to its electrical property.

(b) Describe and explain how the water pump is turned on when it rains heavily. [2]

Answer: When it rains heavily, more water enters the metal container through G and the rising water level brings the wooden block up. Eventually, the metal sheet makes contact with the metal rods and this will complete the circuit. Hence, electric current flows in the circuit and the water pump is turned on.

Explanation: As explained in the Answer.

Comments: Students tend to skip step and miss out details on how the circuit can be closed. PSLE may require keywords such as “closed circuit”, hence the following may be a better answer: “Eventually, the metal sheet makes contact with the metal rods and this will form a closed circuit. Hence, electric current flows in the circuit and the water pump is turned on.”

Tips: Use keywords for electrical system question such as “closed circuit” and “electric current flows”

(c) Without using different apparatus, suggest one way to turn on the water pump when it rains less heavily. Explain your answer. [1]

Answer: Lower the position of the metal rods.  

Explanation: When it rains less heavily, less water enters the container, so the water will rise to a lower level. In order for the metal sheet at a lower position to make contact with the metal rods, the metal rods can be moved to a lower position.

Comments: Students tend to be inspecific and would write “Change the position of the metal rods.” The question also requires an explanation for the suggestion though it is a 1-mark question. Hence, a complete answer would be: “ Lower the position of the metal rods so that less water is needed to enter the metal container to form a closed circuit with the metal rods.”

Tips: Students can look out for comparison word in  “rain less heavily” to know that they need to use comparison word such as “lower”.

Hope this article benefits your children in writing a more accurate and complete answer for the PSLE science questions and that he/she would score better in the examinations.

Here’s another Primary Science exam paper analysis for you: 2018 PSLE Science Exam Paper Analysis