All Definitions

Unit 1

  1. Fundamental Quantity is a quantity from which others can be derived.

Examples of Fundamental Quantity

  • length is the amount by which two points are separated. (Unit: meters, Symbol: m)

  • mass is a measure of the amount of matter that a body contains. (Unit: kilograms, Symbol: kg)

  • time is a measure of the interval between events. (unit: seconds, symbol: s)

  • electric current is the rate of the flow of charge in a circuit. (Unit: Amperes, Symbol: A)

  • thermodynamic temperature is a numerical measure of the hotness or coldness of a body. (Unit: Kelvin, Symbol: k)

  • amount of substance is a measure of the number of entities present in matter. (Unit: mole, Symbol: mol)

  • luminosity is the total amount of energy radiated each second from the surface of a source. (Unit: candela, Symbol: cd)

  1. Unit is a specified specified measure of a physical quantity.

  2. Physical Quantity is a measurable property which is precisely defined.

  3. Homogeneity of Equations refer to the unit on the left hand side of the equation is the same as the unit on the right hand side of the equation.

  4. Scale is a set of marks (or gradations) at intervals on a measuring instrument.

  5. Sensitivity refer to the response a measuring instrument has to a small change.

  6. Range refers to the size of the interval between the minimum and maximum quantities that an instrument can measure.

Factors contributing to uncertainty in measurements

  • limitations of the measuring device

  • the skills of the user

  • irregularities in the object being measured

  1. An error is the difference between a measured value and the true value.

Types of Errors:

  • Random errors are the errors that affect the measurement in an unpredictable manner where the value fluctuates from one reading to another. It is caused by imperfect observations and inability to reproduce the same measurement due to sudden change. It can be solved by taking many readings and averaging them.

  • A systematic error refer to a consistent deviation from the true value of a measurement. It is caused by the non-zeroing of measuring instruments, the incorrect calibration of measuring instrument and incorrect usage of the instrument by the user.

  1. Precision describes the degree to which several measurements of a single quantity provide similar results.

  2. Accuracy describes the nearness of a measurement to the true value.

Unit 2

  1. Heat is energy transferred from an object of higher temperature to another of lower temperature due to the difference in temperature.

  2. Conduction is the transfer of energy through matter that are in direct contact.

  3. Convection is the process of transferring heat through the movement of liquid or gasses.

  4. Radiation is a heat transfer method that requires no medium.

  5. Radiation is heat transfer through a vacuum.

  6. Heat Capacity is the heat required to raise the temperature by 1k. The unit of of heat capacity is JK-1.

  7. Specific Heat Capacity refers to the quantity of heat needed to raise the temperature of 1kg of a substance by 1k.

Unit 3

  1. A wave is a means of transferring energy between two points

  2. Mechanical Wave is a vibration