Summary

• Description:

  The PDF document comprises Form 2 Physics notes on the topic of Measurement II.

  The topics and sub-topics covered in the document include:

  • Measuring Length with Vernier Calipers
    • Vernier calipers are used for measurements requiring higher accuracy than a metre rule can provide.
    • The instrument has two scales: a main scale and a vernier scale.
    • Its parts are designed for various measurements: the outside jaws measure lengths and external diameters, the inside jaws measure internal diameters, and the tail measures depths.
    • The main scale is marked in centimeters (cm) and millimeters (mm), while the vernier scale has 10 divisions, each being 0.9 mm.
    • The accuracy of the vernier calipers is stated as 0.10 mm.
    • Instructions are given on how to take a reading in two steps: reading the main scale at the zero mark of the vernier scale, and then adding the reading from the vernier scale where its mark aligns perfectly with a mark on the main scale.
    • Worked examples with diagrams are provided to illustrate how to read the instrument and calculate the final measurement.
  • Measuring Length with a Micrometer Screw Gauge
    • This instrument is used to measure small lengths with a high accuracy of 0.01 mm.
    • It features two scales: the sleeve scale and the thimble scale.
    • The sleeve scale is divided into millimeters on its upper part and half-millimeters on its lower part.
    • The thimble scale has 50 equal divisions, with each division representing 0.01 mm.
    • A labeled diagram shows the parts of the instrument, including the jaws, sleeve, thimble, and ratchet.
    • A two-step method for taking readings is described, involving reading the sleeve scale first and then the thimble scale.
    • Worked examples are included to demonstrate how to read the scales and obtain the final measurement.
  • Estimating the Size of a Molecule
    • The notes describe the oil drop experiment as a method for estimating molecular size.
    • The method involves placing a drop of oil with a known volume onto a clean water surface, where it spreads to form a thin, circular patch.
    • The thickness of this oil patch is then calculated using the formula: Thickness = Volume / Area.
    • This thickness is considered the upper limit to the size of an oil molecule.
    • Worked examples are provided to guide the calculation.

  These notes are comprehensive, neat, and printable, making them an excellent resource for students learning about precision measurement instruments. They are also highly suitable for teachers to use for lesson preparation, providing clear instructions, diagrams, and worked examples to reinforce understanding.

• Category:

  Lesson Notes
• Level:

  Form 2
• Subject:

  PHYSICS

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