Measurement Devices for Length, Mass, Time & Volume | Physics for JAMB PDF Download

Length

• Metre rule: The metre rule is a measuring instrument used to measure length. It consists of a long, thin, and straight strip marked with centimeter (cm) and millimeter (mm) divisions. The metre rule is commonly used for measuring relatively large lengths with reasonable accuracy.
• Vernier calipers: Vernier calipers are precision instruments used to measure lengths with greater accuracy. They consist of a main scale and a sliding Vernier scale, which allows for measurements in millimeters (mm) and sub-millimeter increments. Vernier calipers are commonly used in scientific and engineering applications.
• Micrometer: The micrometer, also known as a screw gauge, is a device used for highly accurate measurements of small lengths or thicknesses. It employs a threaded screw mechanism and a calibrated thimble to measure dimensions in micrometers (μm) or thousandths of a millimeter.
• Screw gauge: The screw gauge, similar to the micrometer, is used to measure small lengths or diameters with high precision. It consists of a U-shaped frame with a threaded spindle and a thimble for accurate measurements in millimeters (mm) or fractions of a millimeter.

Mass

• Unit of mass: The unit of mass commonly used in physics is the kilogram (kg). It is a fundamental unit of the International System of Units (SI) and is defined as the mass of the International Prototype of the Kilogram, a platinum-iridium cylinder kept at the International Bureau of Weights and Measures.
• Simple beam balance: A simple beam balance is a device used to measure the mass of an object by comparing it to known masses. It consists of a lever arm with a pivot point and two pans suspended from each end. The object whose mass is to be determined is placed on one pan, while standard masses are placed on the other until equilibrium is achieved.
• Concept of beam balance: The concept behind the beam balance is based on the principle of moments or torque. When the moments on both sides of the beam are balanced, the masses on each side are equal. This allows for the determination of the mass of the object being measured.

Time

• Unit of time: The unit of time used in physics is the second (s). It is defined as the duration of 9,192,631,770 periods of the radiation corresponding to the transition between two hyperfine levels of the ground state of the cesium-133 atom.

Time-measuring devices: Time can be measured using various devices, including:

• Mechanical clocks: Traditional clocks that employ mechanical mechanisms, such as pendulums or gears, to measure and display time.
• Digital clocks: Electronic devices that use digital displays to show time in numerical form.
• Atomic clocks: Highly accurate timekeeping devices that rely on the oscillations of atoms to measure time. Atomic clocks are used as reference standards for timekeeping.

Volume

• Measuring cylinder: A measuring cylinder is a glass or plastic container with a graduated scale used to measure the volume of liquids. It has a narrow cylindrical shape and a broad base for stability. The volume is read by measuring the height of the liquid level in the cylinder.