A constant value resistor and a sliding rheostat are connected in series in the circuit. When the sliding rheostat increases, how does the voltage of the constant value resistor change

reduce
The voltage of series resistance increases with the increase of sliding resistance, and decreases with the increase of fixed resistance
Derivation: the series current is the same, I1 = I2
I1=U1/R1 I2=U2/R2
U1/R1=U2/R2
U1/U2=R1/R2

In a series circuit, there is a resistor, a power supply and a switch
In a series circuit, there is a resistor, a power supply and a switch. If the power supply is closed, then the voltage of the resistor is not equal to the power supply voltage. Why?
Find the right answer

In a series circuit, there is a resistor, a power supply and a switch. If the power supply is closed, the voltage of the resistor is equal to the voltage of the power supply, because the internal resistance of the power supply is generally ignored in junior high school physics

Calculation of current voltage resistance in series circuit
There is a current source 5a, a voltage source 20V and a resistor 6ohm in series
Find the voltage of resistance

No picture
If it is in series, the current in the circuit is the current source, so ur = 5 * 6 = 30V
The simple idea is to connect with the current source in series, and the current is the current source
If you want to use the superposition theorem, if two power sources act on the resistance alone, the result is still 30V

The problem of electrical calculation replacing resistance in junior high school physics
One circuit (power supply, ammeter, key, resistance R1, sliding rheostat R2, voltmeter at both ends of R2, series circuit), power supply voltage is 18V, resistance R1 is 30ohm, sliding rheostat R2 is "100ohm"
2A”
(1) (2) skip
(3) At present, there are three constant resistors, a 40 ohm, B 20 ohm and C 40 ohm
10 ohm, choose a replacement resistor R1. Select the appropriate meter range, requirements: in the process of sliding slide P, do not replace the meter range, two meter pointers can reach full scale and the circuit can work normally
【1】 Range selection: ammeter 0 ~ 0.6A, voltmeter 0 ~ 15V, no problem
【2】 Resistance should be selected____ Replace resistance R1
I feel that both B and C are OK. Why choose C?
PS: don't look for me in the post bar

The maximum range of voltmeter is 15V
Assuming that the rheostat is at the maximum, then the circuit current I = 15 / 100 = 0.15A
At this time, the resistance of R1 is r = (18-15) / 0.15 = 20 Ω
That is to say, if the voltmeter can reach the maximum value, it is necessary to replace the resistance

A constant value resistor and a sliding rheostat are connected in series in the circuit. When the sliding rheostat increases, how does the voltage of the constant value resistor change