讲解图片中这道题---**Textual Information:** **Question Introduction:** 6. 万唯原创 (Wanwei Original) 爸爸买了一件加热马甲, 该马甲有高温和低温两个挡位. 衣服上配有一个20000 mA⋅h的充电宝充当电源. 工作时, 提供给电路的电压为5 V, 如图为加热马甲的内部简化电路图, 电阻 $R_0$、$R_1$、$R_2$均为加热电阻,$R_0$的电阻为5 Ω, 部分参数如表所示. **Circuit Diagram Description (第6题图):** Type: Circuit Diagram Main Elements: * Battery: Represented by the standard symbol for a DC voltage source. * Switch $S_2$: A single-pole, single-throw switch connected in series with the battery. * Switch $S_1$: A multi-position switch with one common terminal connected to one side of the battery/S2 combination. It has three output terminals labeled a, b, and c. * Resistor $R_0$: Connected in series with the switch $S_2$ and the battery. * Resistor $R_1$: Connected between terminal a of switch $S_1$ and the other side of the circuit (after $R_0$ and $S_2$). * Resistor $R_2$: Connected between terminal c of switch $S_1$ and the other side of the circuit. * Connection: Terminal b of switch $S_1$ is connected to the junction between $R_2$ and $R_0$. * Labels: $S_1$, a, b, c, $R_1$, $R_2$, $R_0$, $S_2$. The label "第6题图" is below the diagram. **Table Content:** | 额定电压 | 5 V | | :------------- | :------ | | 高温挡功率 | 6.25 W | | 低温挡功率 | 3 W | **Questions:** (1) 当 $S_2$ 闭合,$S_1$ 接 a、b时, 充电宝可持续供电多久? (2) $R_1$ 的阻值是多少? (3) 小明想在原高温挡功率不变的基础上, 改变原来的低温挡, 使其功率高于原来的高温挡, 只移动 $R_0$ 便能实现这一设计, 请在虚线框内画出设计方案的电路图. **Additional Diagram Description (虚线框内 - 第6题答图):** Type: Circuit Diagram within a dashed box. Main Elements: * This diagram appears identical to the first circuit diagram (第6题图). * It contains a battery symbol, switches $S_1$ (with terminals a, b, c) and $S_2$, and resistors $R_1$, $R_2$, and $R_0$ connected in the same configuration as the first diagram. * The label "第6题答图" is below this diagram. This is likely an area provided for drawing the modified circuit as requested in question (3).