Pearson Edexcel International A Level Physics: Unit 6: planning and evaluating experiments (YPH11) – Practice Questions

These are original questions written for Marlbridge, for revision and practice on this content. They are not reproduced past-paper questions, and they do not replicate the exam’s exact structure, question count or mark tariffs – examination boards hold copyright in their own papers. Use these alongside the official past papers from your board or school.

These questions follow the Pearson Edexcel International Advanced Subsidiary/Advanced Level Physics specification (YPH11), Issue 3. They cover section 6.3 Planning, section 6.4 Implementation and Measurements, and log graphs from the Unit 6 description. Unit 6 is an IA2 unit.

Links: study guide, revision notes, course hub, printable checklist and free diagnostics.

Questions

1. An ammeter reads 0.04 A when no current flows. (a) State what is meant by a zero error. [1] (b) The ammeter later reads 0.52 A in a circuit. Give the corrected reading. [1] (c) Describe one way to check that a digital thermometer is calibrated. [1]

2. A student times a pendulum with a hand-held stopwatch. The period is about 1.0 s and the reaction-time uncertainty is 0.2 s. (a) Find the percentage uncertainty when one period is timed, and when 20 oscillations (total about 20.06 s) are timed. [2] (b) The diameter of a wire is about 0.40 mm. Compare the percentage uncertainty from a micrometer (resolution 0.01 mm) with that from a ruler (resolution 1 mm). [2]

3. A student wants to investigate how the temperature θ of 200 cm³ of hot water in a beaker changes with time t as it cools in the room. Plan the investigation. Include the instruments with range and resolution, a calibration check, how you control other variables, repeats, one safety precaution, and how you would use the data. [9]

4. A student measures the diameter of a metal cylinder, about 25 mm, by holding a 30 cm rule across its end. The student also times 10 oscillations of a mass on a spring by watching the mass reach the top of its motion. Suggest one improvement to each method and give a reason for each. [4]

5. A student investigates how the resistance R of a wire depends on its length l. One reading of R is taken at each of 0.40 m, 0.45 m, 0.50 m, 0.55 m and 0.60 m. (a) Comment on the range of lengths and suggest a better range. [2] (b) Comment on the number of readings. [1]

6. A mass oscillates on a spring. The times for 20 oscillations were measured with a stopwatch reading to 0.01 s.

t20 / s	12.90	16.28	18.96	21.36	23.52
T / s	0.645	0.814	0.948	1.068	1.176
T² / s²	0.416025	0.662596	0.898704	1.140624	1.382976

(a) Identify the fault in the T² row and explain it. [2] (b) Rewrite the T² row correctly. [2] (c) Rewrite the first three values of T so they match the precision of the data. [1]

7. A student labels columns: area A / m, spring constant k / N m, resistivity ρ / Ω m⁻¹, power P / J. Correct each unit. [4]

8. A student heats water with a heater of constant power and records the temperature rise ΔT.

t / min	1.0	2.0	3.0	4.0	5.0
ΔT / °C	2.4	4.8	7.1	9.6	9.1

The first four points lie on a straight line through the origin. Identify the reading that is inconsistent, show why, and say what the student should do. [4]

9. A light sensor reads intensity I (arbitrary units) at distance d from a small lamp. A student plots lg I against lg d.

d / m	0.50	0.75	1.00	1.50	2.00
I	80	36	20	8.9	5.0

Suppose I = kdⁿ. Show that the graph should be a straight line, complete the log values, and use the first and last points to find n and k. [6]

10. The corrected count rate R of a short-lived source is measured every 20 s.

t / s	0	20	40	60	80	100
R / s⁻¹	640	435	296	202	137	93

Explain why ln R against t should be linear, then use the end points to find the decay constant and the half-life. [6]

11. A syringe of trapped air is connected to a pressure sensor. The plunger is moved to each volume and p is read at once. There is one reading at each volume.

V / cm	20	16	14	12	10	8
p / kPa	100	125.0	163	167	200.00	250

(a) Suggest two improvements to the method. [2] (b) Identify and correct three presentation errors in the table. [3] (c) Identify the inconsistent reading and support your choice with a calculation. [2] (d) Explain how a log graph would test whether p is inversely proportional to V. [3] (e) Give one hazard and one precaution. [2]

Answers

1. (a) A zero error is a non-zero reading when the true value is zero. [1] (b) 0.52 − 0.04 = 0.48 A [1] (c) Place it in melting ice and check that it reads 0 °C, or compare it with a second thermometer in the same water. [1] Examiner insight: The zero error is subtracted from the reading, not added. Showing the subtraction makes your method clear.

2. (a) One period: 0.2/1.0 × 100 = 20% [1]. Twenty periods: 0.2/20.06 × 100 = 1.0% [1] (b) Micrometer: 0.01/0.40 × 100 = 2.5% [1]. Ruler: 1/0.40 × 100 = 250%, so the ruler is unsuitable [1] Examiner insight: State the conclusion after comparing the percentages.

3. Any nine of the following points, one each:

• Thermometer from −10 °C to 110 °C with 0.5 °C resolution (or a digital probe), and a stopwatch reading to 0.01 s. [1]
• Calibration: place the thermometer in melting ice and check it reads 0 °C. [1]
• Measure 200 cm³ with a measuring cylinder, record θ every 60 s for about 20 minutes, and record the room temperature θ₀. [1]
• Control: use the same beaker, the same volume of water, and the same position away from draughts. [1]
• Control: fit a lid with a thermometer hole, and stir gently before each reading. [1]
• Repeat the whole run and compare the results, then average. [1]
• Safety: hot water can scald, so use a lid, carry small volumes and keep the beaker on a clamped, stable base. [1]
• Plot ln (θ − θ₀) against t. [1]
• A straight line shows exponential cooling, and the gradient gives −k. [1] Examiner insight: Plans gain credit for named quantities, such as 200 cm³ or every 60 s, and for linking the graph to a final quantity. Vague phrases such as “keep it fair” add little.

4. Cylinder: use two set squares against the cylinder on a flat surface and read the gap with the rule, or use vernier callipers. [1] The ends of the diameter are then fixed, without judging the edges by eye. [1] Spring: place a marker at the equilibrium position and start and stop as the mass crosses it. [1] The mass is moving quickly there, so the timing point is well defined, whereas at the top it pauses. [1] Examiner insight: Naming a change gains little unless you also say which error it removes.

5. (a) The range is only 0.20 m, a factor of 1.5, so the gradient is poorly determined. [1] Use about 0.10 m to 1.00 m. [1] (b) Five points with one reading each cannot show scatter. Take more lengths and repeat each. [1] Examiner insight: Range and number of readings are separate comments, so answer both.

6. (a) The T² values have six decimal places, far more significant figures than the data support. [1] T has only 4 significant figures, so T² can be quoted to no more than 4. [1] (b) 0.4160, 0.6626, 0.8987, 1.141, 1.383 (s²) [2] (c) t20 has 4 significant figures, so T is 0.6450, 0.8140, 0.9480 s [1] Examiner insight: Keep trailing zeros. Writing 0.416 for 0.4160 changes the precision you are claiming.

7. A / m² [1]; k / N m⁻¹ [1]; ρ / Ω m [1]; P / W (or J s⁻¹) [1] Examiner insight: Show the full corrected heading, not only the unit, and make sure it reads sensibly as quantity / unit.

8. The point (5.0, 9.1) is inconsistent. [1] The line predicts 2.4 × 5.0 = 12.0 °C, so it is 2.9 °C low. [1] Repeat the measurement. [1] If the repeat agrees with the line, the reading was a mistake. If it is still low, do not discard it, because heat loss may be reducing the rate of rise. [1] Examiner insight: Stating the expected value from the line is more convincing than saying the point “looks wrong”.

9. lg I = n lg d + lg k, which is a straight line with gradient n and intercept lg k. [1] lg d: −0.301, −0.125, 0.000, 0.176, 0.301. lg I: 1.903, 1.556, 1.301, 0.949, 0.699. [1] Gradient = (0.699 − 1.903)/(0.301 − (−0.301)) = −1.204/0.602 = −2.00. [1] So n = −2.0, an inverse square law. [1] At d = 1.00 m, lg d = 0, so lg k = 1.301 [1] k = 10^1.301 = 20 (same units as I, times m²). [1] Examiner insight: Use points far apart and keep the minus sign on the gradient. A small triangle magnifies rounding error.

10. R = R₀ e^(−λt), so ln R = −λt + ln R₀, a straight line with gradient −λ. [1] ln R: 6.461 and 4.533 at t = 0 and t = 100 s. [1] Gradient = (4.533 − 6.461)/100 = −0.01928 s⁻¹. [1] λ = 0.0193 s⁻¹ [1] T½ = ln 2/λ = 0.693/0.01928 [1] = 36 s [1] Examiner insight: Give the unit of λ and keep the sign straight: the gradient is −λ, so the gradient is negative but λ itself is positive.

11. (a) Compress slowly and wait for the air to return to room temperature before reading, so the temperature is constant. [1] Repeat each reading and extend the range, for example to volumes above 20 cm³. [1] (b) Heading V / cm should be V / cm³ [1]. 125.0 should be 125 [1]. 200.00 should be 200 [1] (c) The reading at 14 cm³ (163 kPa) is inconsistent: pV = 163 × 14 = 2282, but the others give about 2000. [1] The expected pressure is 2000/14 = 143 kPa. [1] (d) If p ∝ 1/V then p = c/V, so lg p = −lg V + lg c. [1] Plot lg (p / kPa) against lg (V / cm³) and expect a straight line. [1] The gradient should be −1, and the intercept lg 2000 = 3.30. [1] (e) Hazard: the plunger can be forced out or the syringe can burst if the pressure is too high. [1] Precaution: stay within the syringe and sensor limits and wear eye protection. [1] Examiner insight: Treat each part separately: error spotting, calculation and explanation each need their own evidence.

Where marks are usually lost

• Naming an instrument without its range or resolution.
• Timing one oscillation instead of many.
• Listing controlled variables without saying how they are held.
• Giving a hazard with no precaution, or the reverse.
• Quoting calculated values to too many significant figures, or writing units that do not fit.
• Deleting an anomalous point instead of checking it.

Next steps

• Review the revision notes and the study guide.
• Return to the course hub and the printable checklist.
• Take the free 10-minute diagnostics.
• Visit the trial page to book a free trial class.

Official syllabus

Pearson Edexcel International Advanced Subsidiary/Advanced Level in Physics specification (YPH11), Issue 3, Unit 6: Practical Skills in Physics II, sections 6.1 (log graphs), 6.3 and 6.4. Publisher: Pearson Education Limited.