... 2cos(100t / 2)(V) , t tớnh bng giõy (s) Ti mt thi im t1(s) no ú in ỏp ang gim v cú giỏ tr tc thi l 110 (V) Ti thi im t2(s) = t1(s) + 0,005 (s) thỡ in ỏp cú giỏ tr tc thi bng A 110 (V) B 110 (V) ... trỡnh li dao ng ca vt nng l: v(cm / s) 25 t + ) (cm, s) t ) (cm, A.x = 25cos( B x = 5cos( 2 t(s) O 0,1 s) 25 C.x = 25cos( 0, 6t ) (cm, s) D x = 5cos( t + ) (cm, 2 s) Hc cho rng Hi cho tht ... Cõu 17: t vo hai u cun dõy thun cm cú t cm 1/ (H), mt in ỏp xoay chiu n nh Khi in ỏp tc thi l 60 (V) thỡ cng dũng in tc thi qua mch l (A) v in ỏp tc thi bng 60 (V) thỡ cng dũng in tc thi l (A)...