Electronic Circuits I Revision after midterm

Transcription

1 Eletroni Ciruits I Revision fter miterm Dr. Ahme ElShfee, ACU : Fll 2018, Eletroni Ciruits I -1 / 14 -

2 MCQ1 # Question If the frequeny of the input voltge in Figure 2 36 is inrese, the output voltge will The verge vlue of full-wve retifie voltge with pek vlue of 75 V is () 53 V () 47.8 V () 37.5 V () 23.9 V The totl seonry voltge in enter-tppe full-wve retifier is 125 V rms. Negleting the ioe rop, the rms output voltge is () 125 V () 177 V () 100 V () 62.5 V If one of the ioes in Figure opens, the verge voltge to the lo will 4 5 If the pitor vlue in Figure is erese, the output ripple voltge will Dr. Ahme ElShfee, ACU : Fll 2018, Eletroni Ciruits I -2 / 14 -

3 If the is voltge in Figure is erese, the positive portion of the output voltge will 6 7 If the vlue of R3 in Figure is erese, the positive output voltge will Dr. Ahme ElShfee, ACU : Fll 2018, Eletroni Ciruits I -3 / 14 -

4 8 9 The iel output voltge of pitor-input filter is equl to () the pek vlue of the retifie voltge () the verge vlue of the retifie voltge () the rms vlue of the retifie voltge A 60 V pek full-wve retifie voltge is pplie to pitorinput filter. If f = 120 Hz, RL = 10 k, n C = 10 F, the ripple voltge is () 0.6 V () 6 mv () 5.0 V () 2.88 V Line regultion is etermine y () lo urrent () zener urrent n lo urrent () hnges in lo resistne n output voltge () hnges in output voltge n input voltge A 10 V pek-to-pek sinusoil voltge is pplie ross silion ioe n series resistor. The mximum voltge ross the ioe is () 9.3 V () 5 V () 0.7 V () 10 V (e) 4.3 V In ertin positive lmper iruit, 120 V rms sine wve is pplie to the input. The vlue of the output is () V () 169 V () 60 V () 75.6 V Dr. Ahme ElShfee, ACU : Fll 2018, Eletroni Ciruits I -4 / 14 -

5 If the input voltge to voltge tripler hs n rms vlue of 12 V, the output voltge is pproximtely () 36 V () 50.9 V () 33.9 V () 32.4 V When silion ioe is open, DMM will generlly inite () 0 V () OL () pproximtely 0.7 V () pproximtely 0.3 V If one of the ioes in rige full-wve retifier opens, the output is () 0 V () one-fourth the mplitue of the input voltge () hlf-wve retifie voltge () 120 Hz voltge 16 If the input voltge in Figure is inrese from 5 V to 10 V, ielly the output voltge will 17 Dr. Ahme ElShfee, ACU : Fll 2018, Eletroni Ciruits I -5 / 14 -

6 If RL in Figure is remove, the urrent through the zener ioe will 18 If R in Figure is inrese, the urrent to the lo resistor will 19 If the input voltge mplitue in Figure is reue, the mplitue of the output voltge will Dr. Ahme ElShfee, ACU : Fll 2018, Eletroni Ciruits I -6 / 14 -

7 If the is voltge in Figure 3 30 is reverse, the light output of the LED will () A vrtor ioe exhiits () vrile pitne tht epens on reverse voltge () vrile resistne tht epens on reverse voltge () vrile pitne tht epens on forwr urrent () onstnt pitne over rnge of reverse voltges Compre to visile re LED, n infrre LED () proues light with shorter wvelengths () proues light of ll wvelengths () proues only one olor of light () proues light with longer wvelengths An OLED iffers from onventionl LED in tht it () requires no is voltge () hs lyers of orgni mteril in the ple of pn juntion () n e implemente using n inkjet printing proess () oth () n () 24 The internl resistne of photoioe () inreses with light intensity when reverse-ise () ereses with light intensity when reverse-ise Dr. Ahme ElShfee, ACU : Fll 2018, Eletroni Ciruits I -7 / 14 -

8 25 () inreses with light intensity when forwr-ise () ereses with light intensity when forwr-ise A ioe tht hs negtive resistne hrteristi is the () Shottky ioe () tunnel ioe () lser ioe () hotrrier ioe 26 If the input voltge in Figure is reue y 2 V, the zener urrent will 27 If the zener opens in Figure, the output voltge will 28 If the input voltge mplitue in Figure is inrese, the positive output voltge will Dr. Ahme ElShfee, ACU : Fll 2018, Eletroni Ciruits I -8 / 14 -

9 29 30 The thoe of zener ioe in voltge regultor is normlly () more positive thn the noe () more negtive thn the noe () t +0.7 V () groune 31 If the is voltge in Figure 3 30 is inrese, the light output of the LED will A no-lo onition mens tht () the lo hs infinite resistne () the lo hs zero 32 resistne () the output terminls re open () nswers() n () An LED () emits light when reverse-ise () senses light when 33 reverse-ise () emits light when forwr-ise () ts s vrile resistne Compre to innesent uls, high-intensity LEDs 34 () re righter () hve muh longer life () use less power () ll of the ove 35 An infrre LED is optilly ouple to photoioe. When the Dr. Ahme ElShfee, ACU : Fll 2018, Eletroni Ciruits I -9 / 14 -

10 36 LED is turne off, the reing on n mmeter in series with the reverse-ise photoioe will () not hnge () erese () inrese () flutute A lser ioe proues () inoherent light () oherent light () monohromti light () oth () n () 37 In orer for system to funtion properly, the vrious types of iruits tht mke up the system must e () properly ise () properly onnete () properly interfe () ll of the ove (e) nswers() n () 38 If trnsistor with higher DC is use in Figure, the olletor urrent will 39 Dr. Ahme ElShfee, ACU : Fll 2018, Eletroni Ciruits I -10 / 14 -

11 If trnsistor with higher DC is use in Figure, the se urrent will 40 If VCC in Figure is inrese, the se urrent will The three terminls of ipolr juntion trnsistor re lle () p, n, p () n, p, n () input, output, groun () se, emitter, olletor For opertion s n mplifier, the se of n npn trnsistor must e () positive with respet to the emitter () negtive with respet to the emitter () positive with respet to the olletor () 0 V The βdc of trnsistor is its () urrent gin () voltge gin () power gin () internl resistne 44 Question The pproximte voltge ross the forwr-ise se-emitter juntion of silion BJT is () 0 V () 0.7 V () 0.3 V () VBB If the output of trnsistor mplifier is 5 V rms n the input is 100 mv rms, the voltge gin is () 5 () 500 () 50 () If trnsistor with higher DC is use in Figure, the emitter urrent will Dr. Ahme ElShfee, ACU : Fll 2018, Eletroni Ciruits I -11 / 14 -

12 48 If VBB is reue in Figure, the olletor urrent will In pnp trnsistor, the p regions re () se n emitter () se n olletor () emitter n olletor The emitter urrent is lwys () greter thn the se urrent () less thn the olletor urrent () greter thn the olletor urrent () nswers () n () If IC is 50 times lrger thn IB, then is β () 0.02 () 100 () 50 () 500 The is onition for trnsistor to e use s liner mplifier is lle () forwr-reverse () forwr-forwr () reverse-reverse () olletor is When lowerse is use in reltion to trnsistor, it refers to () low resistne () wire resistne () n internl resistne () soure resistne 54 If the mplitue of Vin in Figure is erese, the output voltge mplitue will Dr. Ahme ElShfee, ACU : Fll 2018, Eletroni Ciruits I -12 / 14 -

13 55 RC in Figure is reue in vlue, the vlue of IC(st) will 56 If the trnsistor in Figure is open from olletor to emitter, the olletor voltge will Dr. Ahme ElShfee, ACU : Fll 2018, Eletroni Ciruits I -13 / 14 -

14 If the emitter in Figure eomes isonnete from groun, the olletor voltge will When operte in utoff n sturtion, the trnsistor ts like () liner mplifier () swith () vrile pitor () vrile resistor In sturtion, VCE is () 0.7 V () equl to VCC () minimum () mximum One in sturtion, further inrese in se urrent will () use the olletor urrent to inrese () not ffet the olletor urrent () use the olletor urrent to erese () turn the trnsistor off In trnsistor mplifier, if the se-emitter juntion is open, the olletor voltge is () VCC () 0 V () floting () 0.2 V Dr. Ahme ElShfee, ACU : Fll 2018, Eletroni Ciruits I -14 / 14 -