Xiao Hong wants to measure the current of a circuit, but she can't estimate its size. How should she choose the range of the ammeter? When she connected the ammeter to the circuit, the pointer deflected to the side without scale. What's the reason?

Xiao Hong wants to measure the current of a circuit, but she can't estimate its size. How should she choose the range of the ammeter? When she connected the ammeter to the circuit, the pointer deflected to the side without scale. What's the reason?

Gradually decrease from the maximum range
When the ammeter is connected to the circuit, the pointer deflects to the side without scale

If the range of an ammeter is 3a, but the current of the measured point is about 30a, please design a circuit to enable the ammeter to measure the measured current normally

This is a problem of changing a small range ammeter into a large range ammeter. It is necessary to measure the internal resistance of the ammeter first. In parallel connection, the internal resistance of the ammeter is divided by 10-1, and 10 is the expansion multiple

For the ammeter with two ranges of 0 ~ 0.6A and 0 ~ 3ala, the 0 ~ 0.6A range is used to measure the current in a circuit in a certain measurement, and the 0 ~ 3A scale is used to measure the current
It is found that the pointer is just on the scale line of 2.3A, and the actual measured current is ()
A：0.43A；B：0.46A;C:0.7A;D:2.3A

Just compare
2.3/3=x/0.6
x=0.46A
B