1. When moving the slide of the sliding rheostat, which two terminals will change the resistance? Which direction will the resistance increase? 2. In order to turn the bulb from dark to light, where should the slide of the sliding rheostat be placed before connecting the circuit?

1. When moving the slide of the sliding rheostat, which two terminals will change the resistance? Which direction will the resistance increase? 2. In order to turn the bulb from dark to light, where should the slide of the sliding rheostat be placed before connecting the circuit?

I don't know what you mean, so I suppose four terminals
A B
C D
ABCD is four terminals, there are four connection methods: ABCD ad BC
The resistance of AB and CD will not change no matter how they move
The other two are also related to the current direction. Suppose a goes in and D goes out, then the smaller the scribing direction is, the smaller the resistance is, and the greater the current is. Conversely, the same is true for BC connection
2. The maximum resistance

A sliding rheostat 'requires the slide p to move to the left after being connected into the circuit; the resistance decreases; then the two terminals connected into the circuit are

A line on the left and a line on the middle slide P are enough

When the slide P of the sliding rheostat slides, the reason why the resistance of the access circuit changes is ()
A. The voltage at both ends of the resistance wire changes B. the cross-sectional area of the resistance wire changes C. the length of the resistance wire connected to the circuit changes D. the current intensity through the rheostat changes

When the slide P of the sliding rheostat slides, the length of the resistance wire of the access circuit changes, which leads to the change of the current in the circuit and the voltage at both ends of the sliding rheostat. The reason for the change of the resistance wire of the access circuit is the change of the length of the resistance wire, and the result of the change of the resistance is the change of the current in the circuit and the voltage at both ends of the sliding rheostat There is no change in the cross-sectional area of the resistance wire