Determine the readings of ammeters A_1 and A_2 depicted in the...

In the given circuit diagram, the positive terminal of the $2\text{ V}$ battery is on the left (indicated by the longer line) and the negative terminal is on the right (indicated by the shorter, thicker line).

For the top branch containing ammeter $A_1$, the n-side (vertical line) of the diode is connected to the positive terminal of the battery, and the p-side (triangle) is connected to the negative terminal. Therefore, the diode is reverse-biased.

An ideal diode in reverse bias acts as an open circuit, offering infinite resistance. Thus, no current flows through the top branch, and the reading of ammeter $A_1$ is $0$.

For the bottom branch containing ammeter $A_2$, the $10\Omega$ resistor is connected directly across the $2\text{ V}$ battery.

Using Ohm's law, the current in this branch is:
$I_2 = \dfrac{V}{R} = \dfrac{2}{10} = 0.2\text{ A}$

Therefore, the reading of ammeter $A_2$ is $0.2\text{ A}$.