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Unformatted text preview: itance of the parallel‐plate capacitor + d L
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+ EE1002 Introduction to Circuits and Systems Fig. Parallel plate capacitors If the two conducting plates of length L and width W are separated by a dielectric material of thickness d, then the capacitance of the capacitor will be C A
d where the A WxL is the area of each plate and r 0 where , r , 0 are the permittivity of the dielectric material, the relative permittivity and permittivity of free space respectively. 0 8.85 1012 F / m Table 3.1 Relative permittivity of selected materials Air 1.0 Diamond 5.5 Mica 7.0 Polyester 3.4 Quartz 4.3 Silicon dioxide 3.9 Practical Capacitors Real capacitors have maximum voltage ratings as beyond certain value the dielectric will breakdown. There is a trade‐off between compact size and voltage rating. 64 EE1002 Introduction to Circuits and Systems Electrolytic Capacitors In such capacitors, one of the plates is metallic aluminum or tantalum, the dielectric is an oxid...
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- Winter '14