27. Resistors & DC Circuits

In FIGURE EX28.30, what is the value of the potential at points 1 and 2?

What are the battery current I_bat and the potential difference V₁ - V₂ between points 1 and 2 when the switch in FIGURE P28.55 is (a) open and (b) closed?

For the circuit below, calculate

(a) the voltage V₁ shown, and

(b) the current through the 6-Ohm resistor.

For the circuit below, calculate the voltage across the 100-Ohm resistor.

The circuit shown in Fig. E$25.30$ contains two batteries, each with an emf and an internal resistance, and two resistors. Find the potential difference $V_{ac}$ of point $a$ with respect to point $c$.

An emf source with ε = 120V, a resistor with R = 80.0Ω, and a capacitor with C = 4.00 μF are connected in series. As the capacitor charges, when the current in the resistor is 0.900 A, what is the magnitude of the charge on each plate of the capacitor?

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?

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

The batteries shown in the circuit in Fig. E26.24 have negligibly small internal resistances. Find the current through the 30.0-Ω resistor.

In the circuit shown in Fig. E26.23, ammeter A₁ reads 10.0 A and the batteries have no appreciable internal resistance. What is the resistance of R?

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. E26.34, the 6.0 Ω resistor is consuming energy at a rate of 24 J/s when the current through it flows as shown. What are the polarity and emf ε of the unknown battery, assuming it has negligible internal resistance?

Draw a graph of the potential as a function of the distance traveled through the circuit, traveling cw from V = 0 V at the lower left corner.

A lightbulb is in series with a 2.0 Ω resistor. The lightbulb dissipates 10 W when this series circuit is connected to a 9.0 V battery. What is the current through the lightbulb? There are two possible answers; give both of them.

What is the current through the 10 Ω resistor in FIGURE P28.61? Is the current from left to right or right to left?