19. 變壓器之一次側、二次側之電壓E、電流I、線圈匝數N之關係為?(A)E1/E2 =N1/N2 =I1/I2(B)E2/E1 =N1/N2 =I1/I2(C)E1/E2 =N1/N2 =I2/I1(D)E1/E2 =N2/N1 =I1/I2