Physics Ch 23

24 July 2022
4.7 (114 reviews)
29 test answers

Unlock all answers in this set

Unlock answers (25)
question
When two or more different capacitors are connected in series across a potential source, which of the following statements must be true?
answer
The total voltage across the combination is the algebraic sum of the voltages across the individual capacitors. Each capacitor carries the same amount of charge. The equivalent capacitance of the combination is less than the capacitance of any of the capacitors.
question
Three identical capacitors are connected in series across a potential source (battery). If a charge of Q flows into this combination of capacitors, how much charge does each capacitor carry?
answer
Q
question
Three identical capacitors are connected in parallel to a potential source (battery). If a charge of Q flows into this combination, how much charge does each capacitor carry?
answer
Q/3
question
When two or more different capacitors are connected in parallel across a potential source (battery), which of the following statements must be true?
answer
The capacitor with the largest capacitance has the most charge. The potential difference across each capacitor is the same.
question
A 5-μF, a 7-μF, and an unknown capacitor CX are connected in parallel between points a and b as shown in the figure. What do you know about the equivalent capacitance Cab between a and b?
answer
Cab > 12 μF Cab > CX
question
Four unequal resistors are connected in series with each other. Which one of the following statements is correct about this combination?
answer
The equivalent resistance is more than the largest resistance.
question
When unequal resistors are connected in parallel in a circuit
answer
the potential drop is always the same across each resistor.
question
Identical light bulbs can be attached to identical ideal batteries in three different ways
answer
B, A, C
question
A capacitor C is connected in series with a resistor R across a battery and an open switch. If a second capacitor of capacitance 2C is connected in parallel with the first one, the time constant of the new RC circuit will be
answer
three times a large as before. D) one-half as large as before. E) one-fourth as large as before.
question
A capacitor C is connected in series with a resistor R across a battery and an open switch. If a second capacitor of capacitance 2C is connected in series with the first one, the time constant of the new RC circuit will be
answer
smaller than before
question
A charged capacitor is connected in series with a resistor and an open switch. At time t = 0 s, the switch is closed. Which of the graphs below best describes the charge Q on the capacitor as a function of time t?
answer
Exponential Decrease (Curved downward slope)
question
A 4.0-μF capacitor and an 8.0-μF capacitor are connected together. What is the equivalent capacitance of the combination if they are connected (a) in series or (b) in parallel?
answer
(a) 2.7 μF (b) 12.0 μF
question
A network of capacitors is connected across a potential difference V0 as shown in the figure. (a) What should V0 be so that the 60.0-μF capacitor will have 18.0 μC of charge on each of its plates? (b) Under the conditions of part (a), how much total energy is stored in this network of capacitors?
answer
(a) 1.50 V (b) 13.5 μJ
question
A 5.0-μF capacitor and a 7.0-μF capacitor are connected in series across an 8.0-V potential source. What is the potential difference across the 5.0-μF capacitor?
answer
4.7 V
question
A 2.0-μF capacitor and a 4.0-μF capacitor are connected in series across an 8.0-V potential source. What is the charge on the 2.0-μF capacitor?
answer
11 μC
question
Three capacitors are connected as shown in the figure. What is the equivalent capacitance between points A and B?
answer
1.7 μF
question
Three capacitors are arranged as shown in the figure, with a voltage source connected across the combination. C1has a capacitance 9pF, C2 has a capacitance of 18pF, and C3 has a capacitance of 27 pF. Find the potential drop across the entire arrangement if the potential drop across C2is 257 V.
answer
1500 V
question
Two resistors in series are equivalent to 9.0 Ω, and in parallel they are equivalent to 2.0 Ω. What are the resistances of these two resistors?
answer
3.0 Ω and 6.0 Ω
question
What resistance must be connected in parallel with a 633-Ω resistor to produce an equivalent resistance of 205 Ω?
answer
303 Ω
question
A combination of a 2.0-Ω resistor in series with 4.0-Ω resistor is connected in parallel with a 3.0-Ω resistor. What is the equivalent resistance of this system?
answer
2.0 Ω
question
Three 2.0-Ω resistors are connected to form the sides of an equilateral triangle ABC as shown in the figure. What is the equivalent resistance between any two points, AB, BC, or AC, of this circuit?
answer
1.3 Ω
question
What is the equivalent resistance of the circuit shown in the figure? The battery is ideal and all resistances are accurate to 3 significant figures.
answer
392 Ω
question
Three resistors of 12 Ω, 12 Ω, and 6.0 Ω are connected together, and an ideal 12-V battery is connected across the combination. What is the current from the battery if they are connected (a) in series or (b) in parallel?
answer
(a) 0.40 A (b) 4.0 A
question
For the circuit shown in the figure, R1 = 5.6 Ω, R2 = 5.6 Ω, R3 = 14 Ω, and ε = 6.0 V, and the battery is ideal. (a) What is the equivalent resistance across the battery? (b) Find the current through each resistor.
answer
(a) 9.6 Ω (b) I1 = 0.63 A I2 = 0.45 A I3 = 0.18 A
question
A 3.0-Ω resistor is connected in parallel with a 6.0-Ω resistor. This combination is then connected in series with a 4.0-Ω resistor. The resistors are connected across an ideal 12-volt battery. How much power is dissipated in the 3.0-Ω resistor?
answer
5.3 W
question
Three resistors with resistances of 2.0 Ω, 6.0 Ω, and 12 Ω are connected across an ideal dc voltage source V, as shown in the figure. If the total current in the circuit is I = 5.0 A, what is the current through the 12-Ω resistor?
answer
0.56 A
question
What is the time constant for the discharge of the capacitor in the following figure?
answer
About 2 ms
question
After how many time constants has the voltage across a discharging capacitor decayed to 0.1% of its initial value?
answer
About 7 time constants
question
A 10 x 10^-6 F capacitor initially charged to 20 x 10^-6C is discharged through a 1kohm resistor. How long does it take to reduce the capacitor's charge to 10 x 10^-6C?
answer
About 6.9ms