如圖所示電壓的瞬時表達式為()。
A.u=10sin(50πt-π/4)V B.u=10sin(50πt+π/4)V C.u=10sin(100πt-π/4)V D.u=10sin(100πt+3π/4)V
A.1003W B.1738W C.2317W D.3010W
圖中,交流電壓為10V,若電流表讀數為5A,功率表讀數為40W,則無功功率為()。
A.50乏 B.30乏 C.40乏 D.10乏