Asd Electrical Engineer

THE HONG KONG POLYTECHNIC UNIVERSITY DEPARTMENT OF ELECTRICAL ENGINEERING EE2011/2711 Applied electromagnetics Expt. No. 3 Field Plotting Using Conducting Paper Objectives: 1. 2. 3. tool: To obtain the scene of action pattern for a three-phase busbar administration at selected time instants during the cycle. To familiarize with field plotting using conducting business relationship and smooth-spoken paint. To obtain electrical parameters from field plots. Field-plotting kit (including sheets of carbon-loaded conducting paper, coin paint, connecting wires and sweeping pen) or PASCO Equipotential and Field Mapper; Variable dc power supply; Potential-divider (formed by connecting resistors on a breadboard); digital multimeter. Theory: Equipotentials and Curvilinear Squargons It is evident that along an equipotential lift in that respect can be no electric field (since E = - dV/dx). It follows that a run line moldiness crossbreed an equipotential surface at right angl es. Consider a undersized divisor of an electric field as shown in Fig. 1, where a1 and a2 are dickens equipotential surfaces, X1, X2, X3 and X4 are four electric flux lines. x1 x2 dy d? a2 a1 V V + dV Figure 1 X dx x4 x3 dz d? 1 The get flux passing finished a1 is: d? ? D ? dA where D is the electric flux density of area a1. (1) According to Gausss Law, the surface underlying of the electric flux density must equal the come up charge enclosed: Q ? ? ? ? D ? dA (2) mental talent C ? dQ D ? dzdy D ? dz ? dy dy dy ? ? ? ? 0? r dz ? ? ?dz ? dV dV E ? dx dx dx (3) where ?0 = 8.85 ? 10-12 F/m is the permittivity of free space and ?r is the relative permittivity of the dielectric. If we can decipher equipotentials and flux lines such that they form curving squares (squares with curved sides (see Fig. 2), because dy and dx are equal and the capacitance of each curvilineal square (or cell) will be ?dz. In the system shown in Fig. 2, the dielectric may be considered to be made! up of a large number of such cells in consecutive publication and...If you want to get a full essay, recount it on our website: BestEssayCheap.com

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