Unit 2: Electric Device and Circuit
11 μC
A 3.0- μF capacitor charged to 40 V and a 5.0- μF capacitor charged to 18 V are connected to each other, with the positive plate of each connected to the negative plate of the other. What is the final charge on the 3.0- μF capacitor?
5.7 mJ
A 6.0- μF capacitor charged to 50 V and a 4.0- μF capacitor charged to 34 V are connected to each other, with the two positive plates connected and the two negative plates connected. What is the total energy stored in the 6.0- μF capacitor at equilibrium?
15 C
A light bulb is rated at 30 W when operated at 120 V. How much charge enters (and leaves) the light bulb in 1.0 min?
30 Ω
A resistor of unknown resistance and a 15- Ω resistor are connected across a 20-V emf in such a way that a 2.0-A current is observed in the emf. What is the value of the unknown resistance?
2100
A small bulb is rated at 7.5 W when operated at 125 V. Its resistance (in ohms) is
600 μC
At t = 0 the switch S is closed with the capacitor uncharged. If C = 50 μF, ε = 20 V, and R = 4.0 k Ω, what is the charge on the capacitor when I = 2.0 mA?
+10 W
At what rate is power supplied by the 10-V emf shown below?
6.0 W
At what rate is thermal energy being generated in the 2 R-resistor when ε = 12 V and R = 3.0 Ω?
0.24 mC
Determine the charge stored by C ₁ when C ₁ = 20 μF, C ₂ = 10 μF, C ₃ = 30 μF, and V ₀ = 18 V.
0.18 mJ
Determine the energy stored in C ₂ when C ₁ = 15 μF, C ₂ = 10 μF, C ₃ = 20 μF, and V ₀ = 18 V.
30 μF
Determine the equivalent capacitance of the combination shown when C = 45 μF.
24 V
Determine ε when I = 0.50 A and R = 12 Ω.
0.40 ms
How long will it take a charged 80- μF capacitor to lose 20% of its initial energy when it is allowed to discharge through a 45- Ω resistor?
5.8 μF
If C = 10 μF, what is the equivalent capacitance for the combination shown?
+9.0 V
If R = 2.0 k Ω, C = 4.0 mF, ε = 8.0 V, Q = 20 mC, and I = 3.0 mA, what is the potential difference V b − V a?
12 W
If R ₁ = 3.0 Ω, R ₂ = 6.0 Ω, R ₃ = 12 Ω, and I = 0.50 A, at what rate is heat being generated in R ₁?
5.6 W
If ε = 8.0 V, at what rate is that emf providing energy to the circuit shown below?
1.6
In an RC circuit, how many time constants must elapse if an initially uncharged capacitor is to reach 80% of its final potential difference?
0.60 A
What is the current in the 10- Ω resistor?
0.20 A
What is the current in the 15- Ω resistor when ε = 9.0 V?
7.8 V
What is the magnitude of the potential difference across the 20- Ω resistor?
−22 V
What is the potential difference V B − V A when I = 1.5 A in the circuit segment below?
16 V
What is the potential difference across C ₂ when C ₁ = 5.0 μF, C ₂ = 15 μF, C ₃ = 30 μF, and V ₀ = 24 V?
6.3 mJ
What is the total energy stored by C ₃ when C ₁ = 50 μF, C ₂ = 30 μF, C ₃ = 36 μF, C ₄ = 12 μF, and V ₀ = 30 V?
90 W
What maximum power can be generated from an 18-V emf using any combination of a 6.0- Ω resistor and a 9.0- Ω resistor?
