Using d = 1.5 cm, calculate the average volume V of one glass ball using V = 3.14d³ ÷ 6.
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V ≈ 1.77 cm³
V = 3.14 × 1.5³ ÷ 6 = 3.14 × 3.375 ÷ 6 = 10.5975 ÷ 6 = 1.77 cm³ (3 s.f.).
O Level Physics: Alternative to Practical, questions with answers
Practise 22 real questions on Alternative to Practical from 2024 to 2024. See the answer and explanation as soon as you answer.
22real questions
1paper covered
1exam sessions
About Alternative to Practical in O Level Physics
Alternative to Practical is one of the 14 main topics in our O Level Physics (Cambridge (CAIE) 5054) question bank, and about 3% of its real questions come from it. Tayyari Karo has 22 real questions on this topic from 2024 to 2024, from Paper 4. By difficulty: 16 medium, 4 easy, 2 hard.
Work through the questions below, then open the explanation for each one. Redo the ones you missed a few days later.
Try 8 real questions
These are real past-paper questions. Think of your answer first, then open the explanation.
Calculate the average volume V of one ball using method 2 (VT = 12 cm³ for six balls), to the nearest 0.1 cm³.
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V = 2.0 cm³
V = VT ÷ 6 = 12 ÷ 6 = 2.0 cm³.
Suggest whether method 1 (V = 1.77 cm³) or method 2 (V = 2.0 cm³) gives the more accurate value for the volume of the ball. Explain your answer.
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Method 1 gives the more accurate value.
Method 1 measures a comparatively large length (about 9 cm) on a ruler that can be read precisely to 0.1 cm, giving a small percentage uncertainty; method 2 depends on reading a fairly small volume change on a measuring cylinder graduated only every 1 cm³, so the percentage uncertainty in the small difference (V2 − V1) is much larger.
The student uses the six glass balls, a small beaker and a top-pan (electronic) balance to find the average mass of one glass ball. Describe the method the student uses.
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Place the empty small beaker on the top-pan balance and record its mass (or zero/tare the balance with the beaker on it). Carefully place all six glass balls into the beaker and record the new total mass. Subtract the empty beaker's mass (or read directly if tared) to find the mass of the six balls, then divide this by 6 to find the average mass of one ball.
Weighing all six balls together and dividing by 6 reduces the percentage error compared with trying to weigh one tiny ball alone.
Compare the values of C1 (0.067 °C/s) and C2 (0.033 °C/s). Explain any difference.
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C1 is about twice C2 — the water cools more slowly as time goes on.
By Newton's law of cooling, the cooling rate is proportional to the temperature difference between the water and its surroundings; as the water cools closer to room temperature this difference shrinks, so the rate of cooling decreases.
Describe how C3 (0.20 °C/s) differs from C1 (0.067 °C/s). Explain your answer.
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C3 is much greater than C1 — the water surrounded by iced water cools about 3 times faster.
The temperature difference between the hot water and its surroundings is much greater with iced water (≈0 °C) than with room-temperature air, and the rate of cooling is proportional to this temperature difference (Newton's law of cooling).
State one other variable (besides starting temperature) that should be kept constant to make a valid comparison.
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The volume/mass of hot water used, and the size/type of the inner beaker, should be kept the same in both trials (other acceptable answers: the volume of iced water used, or ensuring both are stirred in the same way before each reading).
Any variable other than the surroundings being tested should be controlled for a fair comparison.
The focal length f is numerically equal to the gradient of the line. Calculate the gradient, showing the values used.
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f ≈ 14.9 cm
Using two well-separated points on the line, e.g. (60, 864) and (100, 1460): gradient = (1460 − 864) ÷ (100 − 60) = 596 ÷ 40 = 14.9 cm.
Sessions with Alternative to Practical questions
| Session | Paper 4 |
|---|---|
| May/June 2024 | 22 |
Common questions
What does the Alternative to Practical topic cover on this page?
22 real O Level Physics (5054) questions on Alternative to Practical from 2024 to 2024, from Paper 4. Each one shows the year, session and paper it came from.
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Yes. Every question shows the correct answer and a short explanation the moment you answer.
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