𝑡 = 𝑖 𝑡 𝑣 𝑡 = !!(#) % = &!'()! *# % • 1周期の平均電⼒は • . 𝑃 = + , ∫ - , &!'()! *# % 𝑑𝑡 = & .% & . = 𝐼/ 𝑉 / • よって,正弦波交流の実効値は振幅の 𝟏 𝟐 となる. 𝜔𝑇 = 2𝜋 cos 2𝜃 = cos! 𝜃 − sin! 𝜃 = 1 − 2 sin! 𝜃 ! 𝑃 = 1 𝑇 & ! " 𝑉#sin# 𝜔𝑡 𝑅 𝑑𝑡 = 𝑉# 𝑇𝑅 & ! " 1 2 1 − cos 2𝜔𝑡 𝑑𝑡 = 𝑉# 2𝑇𝑅 𝑡 − 1 2𝜔 sin 2𝜔𝑡 ! " = 𝑉# 2𝑇𝑅 𝑇 − 1 2𝜔 sin 2𝜔𝑇 + 1 2𝜔 sin 0 = 𝑉# 2𝑇𝑅 ×𝑇 = 𝑉# 2𝑅 = 𝑉 2𝑅 𝑉 2 = 𝐼$𝑉 $