Electric current is an important physical quantity in electricity. Ammeter is a tool for measuring current size, as shown in our miniature physics experiment box and the same dc ammeter as the school lab.,Please observe the physical ammeter and answer the following questions:

(I) exploration and thinking.

(1) According to what sign confirm ammeter? What do the symbols and Numbers on the terminal stand for?

(2) How many ranges are there in the ammeter? What are the dividing values on the scale of different ranges?

(3) How do I read the current value of a pointer?

(4) There are three terminals on the ammeter. How to connect the current meter to the circuit? What problems should be paid attention to when using?

(2) recognize the mark, range and dividing value of the ammeter.

     A careful observation of the ammeter shows that there is a surface on the dial.\"a.\"This is the mark of the ammeter, indicating that the meter is an ammeter; Before using the ammeter, first understand the range and the value of the meter so that the reading can be quickly and accurately.

     The measuring range is the measuring range of the measuring tool. As shown in the figure, there are two rows of Numbers on the dial of the ammeter.\"0-3 a\"And the next line is\"0--0.6 A\",In other words, this ammeter has two ranges.

     So how do you use these two ranges when you use them? It depends on the ammeter on the terminal of the above, we can see that we use the current meter has three terminal, two of the red is positive terminal, which is the negative terminal of black, two red terminal has written the following respectively\"0.6\"And\"3\"The words\"; Access circuit, can only access two terminal at the same time, must be a black terminal (negative terminal) and a red terminal (terminal), so that the ammeter connected to the circuit is only two configurations: the first kind of connection as shown in figure1The marked0.6The terminal block and the black terminal with the \"-\" are connected to the circuit, and the selection is\"0-0.6 A\"; The second connection, as shown here.2\",\"3The red terminal and the black terminal with \"-\" are connected to the circuit, indicating that the selection is\"0-3 a\"Range.