18 Alternating Currents Notes

alternating ul Öõ ent_ (f) e) cp©¥ain the use of a sing©¥e diode for the ha©¥ transfoñ»ãÒ会Þä N p \ '* transfi»rm er and reca©¥©¥ and so©¥ve prob©¥em s using . . į fo r an ideal (e» show an understanding of the ¨¤incip©¥e of operation of a sim p©¥e ironm re using the re©¥ationship ©¥©¥©¥©¥= = for the sinusoida©¥ ©¡se. (d) distinguish betw een r. m . s. a n d peak va©¥ues and reca©¥©¥ and so©¥ve prob©¥em s of the form x = x o s inatt . «c represent an a©¥tem atir©¥g m rrent or an aftem ating voltage by an equation for a sinusoidal aR em ating cu©¥T enL Ob) deduce t» t the m ean pow er in a resistive ©¥oad is half the m axim um pow er cu©¥T ent or vo©¥tage - value and rootm an- s quare (r. m . s . ) va©¥ue as app©¥ied to an a©¥tem ating «a) st©¥ow an understanding of and use the term s period , frequency, peak C an©¢dates shou d be ab©¥e to L E A R N IN G O U T C O M E S 0 R e c t ifica t ion wi th a di od e T r an s m i ss i on of electrica©¥ energy * T h e tra n s fo rm e r R o o t M e a n Square va©¥ue C h a r ac t er isbc s o￠ al lem a t ing cu r ren t s C O N T E N T

S inusoida©¥ a. c . R ectangular a. c. S aw - tooth a. c . currents a©¥ternating E xam p©¥es of a. c . w a v eform s C haracteristics of A n alternating current varies periodica©¥ly w ith tim e i n direction. 18 . 1 C haracteristics of alternating currents answ ers as you go through this topic. H ave funl place? ©¥nstead of answ ering these questions, I will leave you to discover the of alternating current then? W hy is e©¥ectricity supplied in the form of a. c. in the first require d . c. to operatel N ow you are probab©¥y starting to w onder - w hy the need does not hold any practica©¥ advantage over d . c. In fact, m o s t e©¥ectric app©¥iances ©¥n app©¥ications w here e©¥ectricity is used to dissipate energy in the form of heat, a . c. (a. c . ) w hich w as largely brought into the scene by G eorge W estinghouse. success. Y et in less than a decade, d. c. w a s quickly replaced by alternating current w hich generated and supplied direct current (d, c . ) and it earned him great candles " , H e went on to set up the E dison E ©¥ectric lïlum inating C om pany in 1 8 8 0 current m ade a bold claim that he " w ill m ake e©¥ectricity so cheap that only the rich w ill burn W hy a©¥ternating W nen T hom as E dison form ed the E dison E lectric L ight C om pany in 1 8 7 8 , hE ©¥ m roduction Y 5 - 6 P H Y S IC S D E P A R T M E N T R A F F L E S IN S T ©¥T U T ©¥O N 2 0 17 «¤

equare or r. m . s values, ra ther than the average values. value of the sinusoidal alternating current cannot be zero . M ore often, ro o t - m ean - T his indicates that som e pow er ls dissipated In the resistor. T hus the e¨¤ective current, it is independent of the direction of current. resistor. A lthough the Increase in tem perature depends on the m agnitude of the an increase in the internal energy and correspondingly, the tem