In the circuit as shown in the figure, the resistance R1 = 8ohm, R2 = 10ohm, the supply voltage and the resistance of the constant resistance R are unknown. When the switch S is connected to 1, the current representation is 0.2 When the switch S is connected to 2, the possible value of current expression number is between () a and () A. please explain the analysis process, There is no way to send the figure. It is like this: when the switch is connected to 1, the resistance R1 is in series with the constant resistance R; when the switch is connected to 2, the resistance R2 is in series with the constant resistance R. in both States, the ammeter is in series with the constant resistance

In the circuit as shown in the figure, the resistance R1 = 8ohm, R2 = 10ohm, the supply voltage and the resistance of the constant resistance R are unknown. When the switch S is connected to 1, the current representation is 0.2 When the switch S is connected to 2, the possible value of current expression number is between () a and () A. please explain the analysis process, There is no way to send the figure. It is like this: when the switch is connected to 1, the resistance R1 is in series with the constant resistance R; when the switch is connected to 2, the resistance R2 is in series with the constant resistance R. in both States, the ammeter is in series with the constant resistance

When switch S is connected to 2, the possible value of current expression number is between (0.2) a and (0.25) A. please explain the analysis process. Thank you. U = (8 + R) * 0.2 = (10 + R) * II = 0.2 * (8 + R) / (10 + R) when R is infinite, I & gt; 0.16 when R is infinite, I & lt; 0.20.16 & lt; R & lt; 0.2

The resistor R1 with 6 ohm resistance and unknown resistor R2 are connected in series, and the voltage at both ends of R2 is 6 v
If R1 and R2 are connected in parallel and connected in the same circuit, the measured current through R2 is 6 a
1. Power supply voltage 2. Resistance value of R2

Suppose the supply voltage is UVs,
According to the meaning of the title:
In series: 6 = u * R2 / (6 + R2)
In parallel: u = 6r2
So we can get: R2 = 3 ohm, u = 18V

Calculation formula of total resistance of parallel circuit R and = R1. R2 + R2?
R1.R2
R and = --- this formula was given by the teacher. If we add an R3, how can we deduce it or this formula?
R1+R2
.

∵ in parallel circuit, I = I1 + I2 +. In
I total = u ／ r total I total = U1 ／ R1 + U2 ／ I2 +. + UN ／ RN
That is, u ／ r total = U1 ／ R1 + U2 ／ I2 +. + UN ／ RN
Also ∵ u total = U1 + U2 +... UN in parallel circuit
1 / rtotal = 1 / R1 + 1 / r2 =... + 1 / RN
You should be able to add fractions, so r and = (R2 * R3 + R1 * R3 + R1 * R2) / R1 * R2 * R3
Got it, I don't know how to score. It looks better when you write on paper. Hope to adopt it. Thank you