$26\mathrm{.}29*$ In the circuit shown in Fig. E$26\mathrm{.}29$ the batteries have negligible internal resistance and the meters are both idealized. With the switch $S$ open, the voltmeter reads $17\mathrm{.}0$ V $.($a$)$ Find the emf $$ of the battery. $($b$)$ What will the ammeter read when the switch is closed?

Figure E$26\mathrm{.}2!$