1. 1 Chapter 1: Units and Dimensions  SI Mechanical Units –Fundamental Units Length: meter (m) Mass: kilogram (kg) Time: second (s) –Derived Units Meter Squared (m 2 ) Liter –Unit of Force Newton (N): the force which will give a mass of 1 kilogram an acceleration of 1 meter per second per second.

2. 2 –Work (joule (J)) The work done in moving a body is the product of the force and the distance through which the body is moved in the direction of the force. The joule is defined as the amount of work done when a force of 1 newton acts through a distance of 1 meter. The joule may also be termed a newton-meter. –Energy: the capacity for doing work, joule (J) –Power: the time rate of doing work If a certain amount of work W is to be done in a time t, the power required is The Watt is defined as the power developed when 1 joule of work is done in 1 second.

3. 3  Scientific Notation and Metric Prefixes –Scientific Notation: very large or very small numbers are conveniently written as a number multiplied by 10 raised to a power –Metric Prefixes: a letter symbols for the various multiples and submultiples of 10 –Engineering Notation: Symbol, e.g., T for tera, G for giga, M for mega, and k for kilo.

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5. 5  SI Electrical Units –Units of Current and Charge Ampere (A): the unit of electric current and is defined as that constant current which, when flowing in each of two infinitely long parallel conductors 1 meter apart, exert a force of of length of each conductor Coulomb (C) is defined as that charge which passes a given point in a conductor each second, when a current of 1 ampere flows.

6. 6 –Emf, Potential Difference, and Voltage Volt (V): is the unit of electromotive force (emf) and potential difference. The volt is defined as the potential difference between two points on a conductor carrying a constant current of 1 ampere when the power dissipated between these points is 1 watt. –Resistance and Conductance Ohm (  ): is defined as that resistance which permits a current flow of 1 ampere when a potential difference of 1 volt is applied to the resistance. Conductance (G): is applied to the reciprocal of resistance. The siemens (S) is the unit of conductance.

7. 7 –Magnetic Flux and Flux Density Weber (Wb): is defined as the magnetic flux which, linking a single-turn coil, produces an emf of 1 V when the flux is reduced to zero at a constant rate in 1 s Tesla (T): is the flux density in a magnetic field when 1 weber of flux occurs in a plane of 1 square meter; i.e., 1 Wb/m 2 –Inductance The inductance of a circuit is 1 henry (H) when an emf of 1 volt is induced by the current changing at the rate of 1 A/s. –Capacitance The farad (F): is the capacitance of a capacitor that contain a charge of 1 coulomb when the potential difference between its terminals is 1 volt

8. 8  SI Temperature Scales –Celsius scale; has 100 equal divisions (or degrees) –Kelvin scale (absolute scale) Commences at absolute zero temperature (-273.15 o C)  Dimensions

9. 9  Standards –International Standards Defined by international agreements and maintained at the International Bureau of Weights and Measures in France –Primary Standards Maintained at institutions in various countries around the world Main function: Checking the accuracy of secondary standards –Secondary Standards Employed in industry as references for calibrating high-accuracy equipment and components and for verifying the accuracy of working standards –Working Standards Used as measurement references on a day-to-day basis in all electronics lab