A、保持U<sub>ccsub>,R<sub>Bsub>一定,减小R<sub>csub> B、保持U<sub>ccsub>,R<sub>Bsub>一定,增大R<sub>csub>
A、保持U<sub>ccsub>,R<sub>Bsub>一定,减小R<sub>csub> B、保持U<sub>ccsub>,R<sub>Bsub>一定,增大R<sub>csub>
A、r<sub>1sub>=r<sub>2sub>=0,L<sub>1sub>=L<sub>2sub>=M=0 B、r<sub>1sub>=r<sub>2sub>=0,L<sub>1sub>=L<sub>2sub>=M=∞ C、r<sub>1sub>=r<sub>2sub>=∞,L<sub>1sub>=L<sub>2sub>=M=0 D、r<sub>1sub>=r<sub>2sub>=∞,L<sub>1sub>=L<sub>2sub>=M=∞
A、R<sub>Asub>:R<sub>Bsub>=2,T<sub>Asub>:T<sub>Bsub>=2 B、R<sub>Asub>:R<sub>Bsub>=1/2,T<sub>Asub>:T<sub>Bsub>=1 C、R<sub>Asub>:R<sub>Bsub>=1,T<sub>Asub>:T<sub>Bsub>=1/2 D、R<sub>Asub>:R<sub>Bsub>=2,T<sub>Asub>:T<sub>Bsub>=1
A、R<sub>0sub>、R<sub>50sub>;R<sub>0sub>、R<sub>100sub> B、R<sub>0sub>、R<sub>100sub>;R<sub>100sub>/R<sub>0sub> C、R<sub>100sub>/R<sub>0sub>;R<sub>0sub>/R<sub>100sub> D、R<sub>0sub>/R<sub>100sub>;R<sub>0sub>、R<sub>50sub>
A、(R<sub>1sub>+R<sub>2sub>)/R<sub>1sub>R<sub>2sub> B、R<sub>1sub>R<sub>2sub>/(R<sub>1sub>+R<sub>2sub>) C、R<sub>1sub>+R<sub>2sub> D、R<sub>1sub>R<sub>2sub>
A、串联型稳压电路如图所示,设V<sub>BE2sub>=0.7V,稳压管V<sub>zsub>=6.3V,R<sub>2sub>=350Ω。<br /> (1)若要求V<sub>Osub>的调节范围为10~20V,则R<sub>1sub>及R<sub>wsub>应选多大?<br /> (2)若要求调整管T<sub>1sub>的压降V<sub>CE1sub>不小于4V,则变压器次级电压V<sub>2sub>(有效值)至少应选多大?(设滤波电容C足够大)。<br /> rc="https://img.ppkao.com/2019-04/wuacheng/2019042616184549829.jpg" />
A、R<sub>1sub>与R<sub>3sub>串联后与R<sub>2sub>并联 B、R<sub>1sub>与R<sub>3sub>并联后与R<sub>2sub>串联 C、R<sub>1sub>与R<sub>2sub>并联后与R<sub>3sub>串联 D、R<sub>1sub>与R<sub>2sub>串联后与R<sub>3sub>并联
A、R<sub>xosub>>R<sub>jsub>>R<sub>tsub> B、R<sub>xosub><R<sub>jsub><R<sub>tsub> C、R<sub>xosub>=R<sub>jsub>>R<sub>tsub> D、R<sub>xosub>≈R<sub>jsub><R<sub>tsub>
A、R<sub>1sub>>R<sub>2sub>>R<sub>3sub> B、R<sub>1sub><R<sub>2sub><R<sub>3sub> C、R<sub>1sub>>R<sub>3sub>>R<sub>2sub> D、R<sub>3sub>>R<sub>1sub>>R<sub>2sub>
A、R<sub>1sub>>R<sub>2sub>>R<sub>3sub> B、R<sub>1sub><R<sub>2sub><R<sub>3sub> C、R<sub>1sub>>R<sub>3sub>>R<sub>2sub> D、R<sub>2sub>>R<sub>1sub>>R<sub>3sub>