What is the force between two protons?

• frictional

• neutral

• attractive

• repulsive

What happens when two materials are charged by rubbing against each other?

• both lose electrons

• both gain electrons

• one loses electrons

• no movement of electrons

Which of the following materials are good insulators?

• copper and gold

• wood and glass

• gold and aluminum

• plastic and copper

Which switches must be closed for both the bell to ring and the lamp to light?

• 1 and 4 only

• 2 and 3 only

• 1, 2 and 3 only

• 1, 2, 3 and 4

Which statement does NOT describe how electric changes affect each other?

• positive and negative charges attract

• positive and negative charges repel

• two positive charges repel

• two negative charges repel

关于电源和电流，下列说法中正确的是

• 电流是由大量电荷的无规则运动形成的

• 电源外部，电流是从电源的正极流向负极

• 在电路中只要有电源，就一定会有电流

• 电路中电子移动的方向就是电流的方向

甲、乙、丙三个轻质小球，两两相互吸引，其中一个是带电体，则下列说法正确的是

• 甲一定带正电，乙一定带负电，丙一定不带电

• 甲一定带负电，乙一定带正电，丙一定不带电

• 三个小球中肯定有一个不带电

• 肯定甲不带电

如图所示，开关s闭合时，电路可能发生的情况是

• 灯L1发光，L2不发光

• 电池被烧坏

• 灯L1灯丝被烧坏

• 灯L2灯丝被烧坏

电路中有两只灯泡，当开关闭合时两盏灯同时亮，断开时两盏灯同时熄灭，说

明这两盏灯的连接是

• 一定是串联

• 一定是并联

• 可能是串联或并联

• 以上说法都不对

如图所示，开关由闭合到断开，电流表A₁、A₂的示数I₁、I₂

的变化是

• I₁变小、I₂变大

• I₁不变、I₂变大

• I₁变大、I₂变小

• I₁不变、I₂变小