Fundamental electrical and electronic principles 3rd ed

Electronic devices and amplifier circuits with MATLAB applications

[...]... units consumed can be calculated by multiplying the power (in kW) by the time interval (in hours) So, for the heater mentioned above, the number of ‘units’ consumed would be written as 36 kWh It should be apparent from this that to record this particular figure, fewer dials are required, and their speed of rotation is perfectly acceptable 19 20 Fundamental Electrical and Electronic Principles Worked Example... was 30 km Over the next two hours a further 10 km was travelled, and subsequently no further distance was travelled Since distance travelled divided by the time 5 6 Fundamental Electrical and Electronic Principles s (km) 40 δ s2 30 δ t2 20 δ s1 10 t (h) 0 1 2 3 4 5 δ t1 Fig 1.2 taken is velocity, then the graph may be used to determine the speed of the vehicle at any time Another point to note about this... been 9p, and the standing charge remained unchanged A Total bill ϭ £78.75; standing charge ϭ £15.00; units used ϭ 750 ϭ 750 kWh (a) Cost of the energy (units) used ϭ total Ϫ standing charge ϭ £78.75 Ϫ £15.00 ϭ £63.75 £63.75 ϭ £0.085 750 so, cost/unit ϭ 8.5 p Ans Cost/unit ϭ (b) If the cost/unit is raised to 9p, then cost of energy used ϭ £0.09 ϫ 750 ϭ £67.50 total bill ϭ cost of units used ϩ standing... speaking, means ‘direct current’ However, it is also used to describe unidirectional voltages Thus a d.c voltage refers to a unidirectional voltage that may only be reversed as stated above However, the other commonly used form of electrical supply is that obtained from the electrical mains This is the supply that is generated Fundamentals and distributed by the power companies This is an alternating or... subject matter, and in the main, follow the order of objectives stated in the BTEC unit of Electrical and Electronic Principles The major exception to this is that the topics of instrumentation and measurements do not appear in a specific chapter of that title Instead, the various instruments and measurement methods are integrated within those chapters where the relevant theory is covered Occasionally... slope Fig 1.3 as you trace its path from left to right it is called a positive slope If it slopes downwards it is called a negative slope 1.6 Basic Electrical Concepts All matter is made up of atoms, and there are a number of ‘models’ used to explain physical effects that have been both predicted and subsequently observed One of the oldest and simplest of these is the Bohr model This describes the atom... ϫ 10Ϫ6 ϫ 15 Q ϭ 1.8 mC Ans 9 10 Fundamental Electrical and Electronic Principles Worked Example 1.6 Q 80 coulombs of charge was transferred by a current of 0.5 A Calculate the time for which the current flowed A Q ϭ 80 C; I ϭ 0.5 A Q seconds I 80 ϭ 0.5 t ϭ 160 s Ans tϭ Electromotive Force (emf) The random movement of electrons within a material does not constitute an electrical current This is because... into this effect He reached the conclusion that the amount of heat so produced was proportional to the value of the square of the current flowing and the time for which it flowed Once more a constant of proportionality is required, and again it is the resistance of the circuit that is used Thus the heat produced (or energy dissipated) is given by the equation W ϭ I 2 Rt joule (1.7) and applying Ohm’s law... of electricity; the use of standard form and its adaptation to scientific notation; SI and derived units; and the plotting of graphs This chapter is intended to provide a means of ensuring that all students on a given course start with the same background knowledge Also included in this chapter are notes regarding communication In particular, emphasis is placed on logical and thorough presentation of... kWh and cost ϭ 106.25 ϫ 7.902 ϭ £8.40 Ans s Note: When calculating energy in kWh the power must be expressed in kW, and the time in hours respectively, rather than in their basic units of watts and seconds respectively Worked Example 1.15 Q An electricity bill totalled £78.75, which included a standing charge of £15.00 The number of units charged for was 750 Calculate (a) the charge per unit, and (b) . x0 y0 w1 h1" alt="" Fundamental Electrical and Electronic Principles This page intentionally left blank Fundamental Electrical and Electronic Principles Third Edition Christopher R. objectives of the BTEC unit Electrical and Electronic Principles, some chapters have been removed and some exchanged with the companion book Further Electrical and Electronic Principles, ISBN 9780750687478 study of Electrical and Electronic Engineering. Fundamental Electrical and Electronic Principles contains 349 illustrations, 112 worked examples, 26 suggested practical assignments and 234