【简答题】已知 i1 = 5sin314 t A, i2 = 5sin(314 t +90°) A。计算i=i1+i2。
【单选题】非正弦周期电流电路的电流有效值计算为()。
【单选题】男性,58岁,干部,胸骨后剧烈疼痛2小时用硝酸甘油舌下含服不缓解急诊入院,心电图Ⅱ、Ⅲ、avF出现ST段抬高,最有价值的治疗措施是 ( )
【单选题】.男性,58岁,干部,胸骨后剧烈疼痛2小时,用硝酸甘油舌下含不缓解,急诊入院。心电图II.III.avF出现ST段抬高,最有价值的治疗措施是
【单选题】男性,58岁,干部,胸骨后剧烈疼痛2小时用硝酸甘油舌下含不缓解急诊入院,心电图Ⅱ、Ⅲ、avF出现ST段抬高,最有价值的治疗措施是
【单选题】某非正弦周期电流电路的电压为 ,电流 ,则其三次谐波的功率P3是( )W。
【简答题】非正弦周期电流电路的功率因数并不代表电路______,仅代表电路______。
【简答题】1 Candidate A was late because he couldn’t find the address, his phone battery was dead and the parking was _______. 2 Candidate A worked _______ hours in his last job. 3 Candidate A thought he would ...
【判断题】已知 i 1 = 5sin314 t A, i 2 = 15sin(942 t +90°) A。则 i 2 比 i 1 超前 90 °。