Exam 29: Direct Current Dc Circuits

At t = 0 the switch S is closed with the capacitor uncharged. If C = 30 μF, ε = 30 V, and R = 5.0 kΩ, at what rate is energy being stored in the capacitor when I = 2.0 mA?

Determine the resistance R when I = 1.5 A.

A parallel circuit consists of a 100-V DC power source, a 100-Ω resistor, and a variable resistor of resistance R, which varies from 0 to 100 Ω. The current in the circuit is ​ ​

A 10-V battery is connected to a 15-Ω resistor and an unknown resistor R, as shown. The current in the circuit is 0.40 A. How much heat is produced in the 15-Ω resistor in 2.0 min?

An initially uncharged 10-μF capacitor is charged by a 10-V battery through a resistance R. The capacitor reaches a potential difference of 4 V in a period of 3 s after the charging began. Find the value of R.

What is the equivalent resistance between points A and B in the figure when R = 10 Ω?

Determine the current in the 10-V emf.

What is the potential difference Vb − Va shown in the circuit below.

Determine the potential difference Va − Vb shown in the circuit below.

The circuit below contains 5 identical light bulbs. The emf is 110 V. Which light bulb(s) is(are) brightest?

What is the potential difference VB − VA when I = 1.5 A in the circuit segment below? ​ ​

The circuit below contains three resistors, A, B, and C, which all have equal resistances. The emf ε = 110V. Which resistor generates the most thermal energy after the switch is closed?

The circuit below contains 3 100-W light bulbs and a capacitor. The emf is 110 V. Which light bulb(s) is(are) brightest? (Assume the capacitor is fully charged.)

A certain brand of hot dog cooker applies a potential difference (120 V) to opposite ends of the hot dog and cooks by means of the joule heat produced. If 60 kJ is needed to cook each hot dog, what current is needed to cook four hot dogs simultaneously in 3.0 min?

If Q = 350 μC and I = 4.0 mA in the circuit segment shown below, determine the potential difference, VA − VB.

A circuit consists of N resistors, all of resistance R, connected as shown below. A potential difference V is applied to the circuit. The equivalent resistance of the circuit is

A 5000-Ω resistor and a 50-μF capacitor are connected in series at t = 0 with a 6-V battery. The capacitor is initially uncharged. What is the current in the circuit at t = 0? At t = 0.5 s? What is the maximum charge stored on the capacitor?

At t = 0 the switch S is closed with the capacitor uncharged. If C = 50 μF, ε = 20 V, and R = 4.0 kΩ, what is the charge on the capacitor when I = 2.0 mA?

What is the potential difference VB − VA when I = 0.50 A in the circuit segment shown below?

What is the equivalent resistance between points a and b when R = 12 Ω?