In the circuit below, $4$ resistors are wired to a battery. The circuit has four points of interest in the corners marked by a through $d.$ The symbol of the A with the circle around it will represent the symbol for an ammeter $($to measure current$),$ and the symbol of the $V$ with a circle around it will represent a voltmeter $($to measure voltage$).$

In this circuit, students find that the value of $V_1$ is $7\mathrm{.}5$ volts. So the potential difference between points $c$ and $b$ is $7\mathrm{.}5$ volts. Using this information,

A$.$ determine the current reading of the ammeter.

B$.$ Determine what the reading of $V_2$ would be$.$ This will be the voltage difference between points a and $b.$

C$.$ What is the value of the supply voltage?