The 10.00 V battery in Fig. E26.28 is removed from the circuit and reinserted with the opposite polarity, so that its positive terminal is now next to point a. The rest of the circuit is as shown in the figure. Find the current in each branch.

The 5.00 V battery in Fig. E26.28 is removed from the circuit and replaced by a 15.00 V battery, with its negative terminal next to point b. The rest of the circuit is as shown in the figure. Find the current in each branch.

In the circuit shown in Fig. E26.27 find the current in the 3.00 Ω resistor.

Find the emfs ${\epsilon }_1$ and ${\epsilon }_2$ in the circuit of Fig. E26.26, and find the potential difference of point $b$ relative to point $a$.

In the circuit shown in Fig. E26.31 the batteries have negligible internal resistance and the meters are both idealized. With the switch S open, the voltmeter reads 15.0 V. What will the ammeter read when the switch is closed?

In the circuit shown in Fig. E26.27 find the unknown emfs ${\epsilon }_1$ and ${\epsilon }_2$.

In the circuit shown in Fig. E26.33 all meters are idealized and the batteries have no appreciable internal resistance. Find the reading of the voltmeter with the switch S open. Which point is at a higher potential: a or b?