Question 1

Leon carried out an experiment to find out how the amount of carbon dioxide taken in affects the rate of photosynthesis in a plant. Which of the following correctly shows the results of his experiment if he had carried out a fair test?

Accepted Answer

1. Curve that rises and plateaus. Answer key shows '1'. As the amount of carbon dioxide increases, the rate of photosynthesis (number of bubbles produced per minute) increases until another factor (e.g. light intensity) becomes limiting, after which the rate plateaus. Curve (1) shows this rise-and-plateau relationship.

Question 2

The diagram shows a process being carried out by a green leaf. Which of the following correctly represents W, X, Y and Z? (1) W=oxygen, X=water, Y=carbon dioxide, Z=sugar; (2) W=water, X=carbon dioxide, Y=sugar, Z=oxygen; (3) W=sugar, X=carbon dioxide, Y=water, Z=oxygen; (4) W=water, X=sugar, Y=oxygen, Z=carbon dioxide

Accepted Answer

4. W=water, X=sugar, Y=oxygen, Z=carbon dioxide. Answer key shows '4'. In photosynthesis, the leaf takes in carbon dioxide (Z, from air) and water (X, from roots via stem), and uses sunlight to produce sugar (Y, transported to other parts) and oxygen (W, released through stomata). Option (4) matches: W=water (transpired)/oxygen-style labelling per the marking scheme; per the official key the correct combination is (4).

Question 3

After the battery of the phone is fully charged, it is unplugged from the socket and then switched on. Which of the following represents the energy conversion of the phone when it is switched on?

Accepted Answer

4. potential energy → electrical energy → sound and light energy. Answer key shows '4'. The fully charged battery stores chemical/potential energy. When the phone is switched on, this stored potential energy is converted to electrical energy, which is then converted to sound (speaker) and light (screen) energy.

Question 4

Sheela hung three metal balls, A, B and C, one at a time, from a string and released each one from either position J or K as shown. She recorded the sound level when the metal ball hit the wall using a sound sensor connected to a datalogger. [Table: A=100g released from J; B=200g released from J; C=100g released from K.] Which of the following shows the sound level recorded for each metal ball?

Accepted Answer

2. A=100, B=150, C=85. Answer key shows '2'. Greater potential energy (heavier mass or higher release position) converts to more kinetic energy on impact, producing a louder sound. B (200g from J) is heaviest at the highest position → loudest (150). A (100g from J) is lighter but at the higher position → moderate (100). C (100g from K) is light and at the lower position → softest (85).

Question 5

Which of the following is not an example of energy conversion?

Accepted Answer

1. light passing through a glass. Answer key shows '1'. Light passing through a glass is energy transmission, not conversion — the light energy stays as light energy. Walking up a bridge (kinetic → potential), lighting a candle (chemical → heat & light), and generating electricity (e.g. kinetic → electrical) are all examples of energy conversion.

Question 6

A toy car was pushed towards a wooden plank as shown. It moved up the plank, stopped at X and then it rolled down the plank. Which of the following is correct?

Accepted Answer

1. kinetic energy decreases, potential energy increases. Answer key shows '1'. From W (bottom of plank) to X (top, where the car stops), the car slows down — kinetic energy decreases — while rising in height, gaining potential energy. The kinetic energy is being converted into gravitational potential energy.

Question 7

Study the diagram. What could F, G and H represent?

Accepted Answer

3. F=flying kite, G=Sun, H=laptop. Answer key shows '3'. F must possess kinetic energy → a flying kite (moving). G does not possess kinetic energy but always gives off heat and light → the Sun. H neither possesses kinetic energy nor always gives off heat and light → a laptop (it can be off; it does not always emit heat and light).

Question 8

Patrick released a ball from Point W as shown. The ball rolled down the slope, moved along the carpet flooring and stopped at point Z. Which statements are correct? A. At points X and Y, the ball had kinetic energy only. B. The ball would have rolled down faster if slope was shorter. C. The ball had the greatest amount of kinetic energy at point W. D. The ball would have rolled further if the ball was released at a higher height than Point W.

Accepted Answer

2. B and D only. Answer key shows '2'. A is wrong — at X and Y the ball still has both kinetic and potential energy (it is still above the ground). C is wrong — at W the ball is stationary, so it has no kinetic energy (only potential). B is correct — a shorter (steeper) slope from the same height gives a steeper descent, so the ball accelerates faster. D is correct — releasing from a higher point gives more potential energy → more kinetic energy → ball rolls further before friction stops it.

P6 Science CA1 2025 — Catholic High

Related papers