Use an ohmmeter to measure the resistance value of a resistance R, set the selection knob at "× 10" position, and the pointer is in the middle of the 100 and 200 scale arc lines when measuring A. R=150ΩB. R=1500ΩC. 1000Ω＜R＜1500ΩD. 1500Ω＜R＜2000Ω

Use an ohmmeter to measure the resistance value of a resistance R, set the selection knob at "× 10" position, and the pointer is in the middle of the 100 and 200 scale arc lines when measuring A. R=150ΩB. R=1500ΩC. 1000Ω＜R＜1500ΩD. 1500Ω＜R＜2000Ω

The dial of ohmmeter is dense on the left and sparse on the right. The zero scale is on the right. When measuring, the pointer is in the middle of 100 and 200 scales. The number of pointer should be greater than 100 but less than 150. The knob should be set at "× 10", so the resistance value with measuring resistance should be between 1000 and 1500 Ω, so C is correct. So select C

The full bias current of sensitive ammeter is 200uA. Change it into ohmmeter to measure 10K ohm resistance. The needle points to 100ua. When measuring another resistance, it is 50ua. What is the resistance

The full bias current is Ig. The ammeter is changed into ohmmeter, which is connected in series with a power supply (constant voltage, equal to e) and an internal resistance ro. This ro includes the internal resistance of the meter head, the zero resistance, the internal resistance of the power supply, etc

The voltage of 9V is equal to half of 18V, which indicates that the resistance on both sides of the sliding resistance is equal, and both sides are 30 ohm. After closing the switch, the total resistance = 30 * 60 / (30 + 60) + 30 = 50 ohm
How is the circuit parallel or series?

From your formula, we can see that the circuit should be a series parallel hybrid circuit, because the first 30 * 60 / (30 + 60) part is in parallel, and then 30 is in series