Physics Paper 6 Practical
Notes 2025 – Common
Experimental Errors,
Corrections, and Exam
Guidance
,General Measurement and Setup Issues in light ray expirement either using a mirror or a rectangular prism
• Pins might not stand upright.
• Aligning pins accurately can be difficulty.
• Pins or drawn lines may be too thick, leading to inaccuracy.
• The block outline might appear larger than the actual block.
• Mirror thickness affects measurements.
Improvements:
• Keep at least 5 cm between pins.
• Ensure pins are vertical and view their bases at eye level.
• Use thin pins and fine/thin pencil lines (sharp pencil) for clarity.
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Thermometer and Heat Experiments
• Stir the liquid before taking temperature readings to ensure uniform/even
heat distribution.
• View the thermometer scale petpendicularly/at right angles to prevent
parallax errors.
• Wait for the temperature to stabilize/themometer reading to stop rising before
recording.
• Make sure the thermometer bulb doesn’t touch the container walls/ base or
sides of the beaker.
• Use lids, insulation, or mats to reduce heat loss from the top, sides,
and bottom respectively.
• Keep variables constant such as room temperature, starting temperature,
beaker type, and water volume.
Example Question:
Why stir the water before reading the temperature?
→ To ensure even heat distribution and uniform temperature.
How to increase cooling rate?
→ Use hotter water, a metal container, cooler surroundings, a fan, or a
container with a larger surface area.
⸻
, Measuring Cylinder and Volume Experiments
• View the scale perpendicularly, or at right angles l to avoid parallax.
• Record from the bottom of the meniscus.
To find volume of an irregularly shaped object
(may be used in expirements to find the density of an irregularly shaped object)
• Immerse objects gently to avoid splashing.
• Take multiple readings and average them.
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Balancing and Lever Experiments
• The ruler or load may slip, or perfect balance may be hard to achieve.
• Mark reference points and average multiple readings for better precision.
• If the load obscures the scale, read from both sides and take the mean value.
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Electrical Circuits
• Wires can overheat; limit/reduce current and switch off between readings to prevent overheating.
• Use a variable resistor to control current for multiple readings.
• Thick crocodile clips can obscure measurement points— so use thinner crocodile clips.
• If a lamp is dim but the meter shows current, the lamp isn’t broken—current is just too small to
light it.
• Remember: ammeters go in series, voltmeters in parallel.
⸻
Optics and Lens Experiments
• The image may only be sharp over a small range of lens positions.
• Some parts of the image can be clear while others are blurred.
• Center of the lens may be difficult to identify—mark it clearly.
• Ensure all apparatus are aligned at the same height and perpendicular to the bench.
• Move the screen or lens until the sharpest image appears.
• To avoid ruler shadows, use a translucent or gridded screen, or a transparent ruler.
Example Question:
How does the image differ from the object?
→ The image is inverted and dimmer than the original.