As shown in the figure is the schematic diagram of the ohm range of the multi-purpose meter, in which the full bias current of the ammeter is 300 μ a, the internal RG = 100 Ω, the maximum resistance of the zero adjusting resistance R = 50K Ω, the fixed resistance in series R0 = 50 Ω, and the battery electromotive force E = 1.5V A. 30kΩ～80kΩB. 3kΩ～8kΩC. 300Ω～800ΩD. 30Ω～80Ω

As shown in the figure is the schematic diagram of the ohm range of the multi-purpose meter, in which the full bias current of the ammeter is 300 μ a, the internal RG = 100 Ω, the maximum resistance of the zero adjusting resistance R = 50K Ω, the fixed resistance in series R0 = 50 Ω, and the battery electromotive force E = 1.5V A. 30kΩ～80kΩB. 3kΩ～8kΩC. 300Ω～800ΩD. 30Ω～80Ω

According to Ohm's law of closed circuit, when full bias: Ig = Er total half bias, 12ig = Er total + R, the simultaneous solution is: r = R total = eig = 1.5v300 × 10 − 6A = 5000 Ω = 5K Ω, so select B

There are five 10 ohm resistors in parallel, and then in series with 2 ohm resistors. What is the total resistance? Why?
I belong to zero basis, so I hope to get a very detailed explanation

In parallel connection, the reciprocal of the total resistance is equal to the reciprocal sum of the partial resistances; in series connection, the total resistance is equal to the sum of the partial resistances. Therefore, for five 10 ohm parallel connections, 1 / RA = 1 / 10 + 1 / 10 + 1 / 10 + 1 / 10, RA = 2 ohm; for two ohm series connections, r = RA + 2 = 4 ohm

There are two resistors. When they are connected in series, the total resistance is 10 ohm. When they are connected in parallel, the total resistance is 24 ohm. How many ohms are these two resistors
The calculation process is also written down
There are two resistors. When they are connected in series, the total resistance is 10 ohm. When they are connected in parallel, the total resistance is 2.4 ohm. How many ohms are these two resistors? Wrong number

R1+R2=10
1/R1+1/R2=2.4
R1=4 R2=6
The two resistors are 4 ohm and 6 ohm respectively

The total resistance of r1r2 in series is 10 ohm, and that of r1r2 in parallel is 2.4 ohm,

R1 + R2 = 10 Ω ①
1 / R1 + 1 / r2 = 1 / 2.4 Ω ②
R1 = 10 euro-r2 obtained by ① is substituted by ②;
1 / (10 euro-r2) + 1 / r2 = 1 / 2.4 Euro
(R2 + 10 euro-r2) / R2 * (10 euro-r2) = 1 / 2.4 Euro
10 Ω / R2 * (10 Ω - R2) = 1 / 2.4 Ω
10 Ω * 2.4 Ω = R2 * (10 Ω - R2)
24 Ω ^ 2 = 10 Ω - R2 ^ 2
R2 ^ 2-10 Ω + 24 Ω ^ 2 = 0
The solution is R2 = 6 or R2 = 4
So when R2 = 6 Ω, R1 = 4 Ω;
So when R2 = 4 Ω, R1 = 6 Ω;