All formulas and experiments, such as voltammetric resistance measurement For example: w = FS Important experiments. Voltammetric resistance and so on. Now

All formulas and experiments, such as voltammetric resistance measurement For example: w = FS Important experiments. Voltammetric resistance and so on. Now

Speed V (M / s) v = s / T S: distance / T: time
Gravity g
(N) G = mg m: mass
g: 8 N / kg or 10 N / kg
Density ρ
（kg/m3） ρ= m/v
m: Quality
5: Volume
Resultant force
(N) Same direction: F = F1 + F2
Opposite direction: F = f 1-f 2 when the direction is opposite, F 1 > F 2
Buoyancy f
(N) F floating = g object - G view g view: gravity of object in liquid
Buoyancy f
(N) F = g, this formula is only applicable
Floating or levitating objects
Buoyancy f
(N) F floating = g row = m row, g = ρ liquid, GV row, g row: the gravity of the liquid
M row: the mass of liquid in row
ρ liquid: density of liquid
V row: volume of liquid to be discharged
(volume immersed in liquid)
Balance condition of lever f1l1 = f2l2 F1: power L1: power arm
F2: resistance L2: resistance arm
Fixed pulley f = g
S = H F: the tension on the free end of the rope
G object: the gravity of an object
S: The distance that the free end of the rope moves
h: The distance an object rises
Moving pulley f = (g object + G wheel)
S = 2 h g object: the gravity of the object
Wheel G: gravity of moving pulley
Pulley block f = (g object + G wheel)
S = N H N: the number of segments of the rope passing through the movable pulley
Mechanical work W
(J) W = FS F: force
s: The distance moved in the direction of the force
Useful work
Total work w total w = g matter H
Wtotal = FS, when the pulley block is placed vertically
Mechanical efficiency η = × 100%
Power p
（w） P=W/t
W: Merit
t: Time
Pressure P
（Pa） P= F/S
F: Pressure
S: Stress area
Liquid pressure P
(PA) P = ρ GH ρ: density of liquid
h: Depth (from liquid level to desired point)
The vertical distance of the
Heat Q
(J) Q = cm △ T C: specific heat capacity m: mass
Δ T: change value of temperature
Fuel emission
Q (J) q = MQ M: mass Q: calorific value
I = u / R (I is current, u is voltage, R is resistance)
W = uit (W electric work, u voltage, t is time)
P = UI (P is electrical power, I is current, u is voltage)
This is all

In the experiment of measuring resistance by voltammetry, what is the function that sliding rheostat can't play?

Sliding rheostat is to change the voltage and current of the resistance value to be measured, at the same time to prevent excessive current, burn out the circuit, no other use

In the experiment of measuring resistance by voltammetry, sliding rheostat has ()
A. Change the current in the circuit B. change the voltage at both ends of the measured resistance C. change the resistance value of the measured resistance D. protect the circuit

A. Moving the slide of the sliding rheostat changes the resistance connected to the circuit and the current in the circuit, which is in line with the meaning of the topic. B. the resistance value of the resistance in the experiment remains unchanged, while moving the slide of the sliding rheostat changes the current in the circuit. According to u = IR, the resistance remains unchanged and the current changes, so the voltage changes at both ends of the measured resistance, which is in line with the meaning of the topic D. when the sliding rheostat is connected to the circuit, the slide slides to the maximum resistance, the resistance is the maximum, the power supply voltage is the same, and the current is the minimum, which plays the role of protecting the circuit, which is in line with the meaning of the topic