27. Resistors & DC Circuits

In a circuit consisting of a $12V$ battery connected in series with a $4\Omega$ resistor and a $2\Omega$ resistor, what is the current through each resistor according to Kirchhoff's Loop Rule?

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?

(III) Determine the time constant for charging the capacitor in the circuit of Fig. 26–69. [Hint: Use Kirchhoff’s rules.] What is the maximum charge on the capacitor?

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?

(I) Calculate the current in the circuit of Fig. 26–51, and show that the sum of all the voltage changes around the circuit is zero.

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 $a$.

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. E26.27 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?

(III) When the resistor R in Fig. 26–72 is 45 Ω, the high-resistance voltmeter reads 9.7 V. When R is replaced by a 14.0-Ω resistor, the voltmeter reading drops to 8.1 V. What are the emf and internal resistance of the battery?