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## 11.4 Chapter summary (ESCQG)

Presentation: 27YS

• Electrical generators convert mechanical energy into electrical energy.

• Electric motors convert electrical energy into mechanical energy.

• There are two types of generators - AC and DC. An AC generator is also called an alternator.

• There are two types of motors - AC and DC.

• Alternating current (AC) has many advantages over direct current (DC) listed previously.

• The root mean square (rms) value of a quantity is the maximum value the quantity can have divided by $$\sqrt{\text{2}}$$.

• RMS values are used for voltage and current when dealing with alternating current, $$I_{\text{rms}} = \dfrac{I_{\text{max}}}{\sqrt{\text{2}}}$$ and $$V_{\text{rms}} = \dfrac{V_{\text{max}}}{\sqrt{\text{2}}}$$.

• The average power dissipated in a purely resistive circuit with alternating current is $$P_{av}=I_{rms}V_{rms}$$.