Question 1

A 5-µF,a 7-µF,and an unknown capacitor C_X are connected in parallel between points a and b as shown in the figure.What do you know about the equivalent capacitance C_ab between a and b? (There could be more than one correct choice. ) A)C_ab > 12 µF B)C_ab > C_X C)5 µF < C_ab < 12 µF D)C_ab < 5 µF E)C_ab < C_X

Accepted Answer

The answer of A 5-µF,a 7-µF,and an unknown capacitor C_X...

Question 2

Suppose you have two capacitors and want to use them to store the maximum amount of energy by connecting them across a voltage source.You should connect them
A)in series across the source.
B)in parallel across the source.
C)It doesn't matter because the stored energy is the same either way.

Accepted Answer

The best way to store the maximum amount of energy in capacitors is to connect them in parallel across the voltage source. When capacitors are connected in parallel, the total capacitance is the sum of individual capacitances. This effectively increases the total surface area of the capacitor plates, allowing for a larger storage of charge and hence more energy. On the other hand, when capacitors are connected in series, the total capacitance decreases as the reciprocal of the sum of the reciprocals of individual capacitances. Hence, the stored energy would be less than that of the parallel connection. Thus, connecting the capacitors in parallel across the source is the best choice.

Question 3

You obtain a 100-W light bulb and a 50-W light bulb.Instead of connecting them in the normal way,you devise a circuit that places them in series across normal household voltage.If each one is an incandescent bulb of fixed resistance,which statement about these bulbs is correct?
A)Both bulbs glow with the same brightness,but less than their normal brightness.
B)Both bulbs glow with the same brightness,but more than their normal brightness.
C)The 100-W bulb glows brighter than the 50-W bulb.
D)The 50-W bulb glows more brightly than the 100-W bulb.

Accepted Answer

When bulbs are connected in series, the bulb with the lower power rating (which corresponds to higher resistance for incandescent bulbs at a given voltage) will glow more brightly. This is because it limits the current for both bulbs, and since power dissipation (brightness) in a resistor (the bulb filament, in this case) is proportional to the square of the current times the resistance, the bulb with higher resistance (the 50-W bulb) ends up dissipating more power in this configuration.

Question 4

Four unequal resistors are connected in series with each other.Which one of the following statements is correct about this combination?
A)The equivalent resistance is equal to that of any one of the resistors.
B)The equivalent resistance is equal to average of the four resistances.
C)The equivalent resistance is less than that of the smallest resistor.
D)The equivalent resistance is less than that of the largest resistor.
E)The equivalent resistance is more than the largest resistance.

Accepted Answer

When resistors are connected in series, the total or equivalent resistance of the combination is the sum of all the individual resistances. Therefore, the equivalent resistance of a series combination is always greater than the resistance of any single resistor in the combination, including the largest one.

Question 5

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?
A)3Q
B)Q
C)Q/3
D)Q/9

Accepted Answer

When capacitors are connected in parallel, they have the same potential difference across them. Therefore, the charge on each capacitor is proportional to its capacitance. In this case, since the capacitors are identical, they share the charge equally. Therefore, each capacitor carries Q/3 charge.

Question 6

A 9-V battery is hooked up to two resistors in series using wires of negligible resistance.One has a resistance of 5 Ω,and the other has a resistance of 10 Ω.Several locations along the circuit are marked with letters,as shown in the figure.Which statements about this circuit are true? (There could be more than one correct choice. ) 
A)The current is exactly the same at points A,B,C,and D.
B)The current at A is greater than the current at B,which is equal to the current at C,which is greater than the current at D.
C)The current at A is greater than the current at B,which is greater than the current at C,which is greater than the current at D.
D)The potential at B is equal to the potential at C.
E)The potential at D is equal to the potential at C.

Accepted Answer

The answer of A 9-V battery is hooked up to...

Question 7

As more resistors are added in parallel across a constant voltage source,the power supplied by the source
A)increases.
B)decreases.
C)does not change.
D)increases for a time and then starts to decrease.

Accepted Answer

When resistors are added in parallel, the overall resistance of the circuit decreases, leading to an increase in the total current drawn from the source. Since power (P) is calculated as P = V * I (where V is the voltage and I is the current), and the voltage remains constant, an increase in current results in an increase in power supplied by the source.

Question 8

As more resistors are added in series to a constant voltage source,the power supplied by the source
A)increases.
B)decreases.
C)does not change.
D)increases for a time and then starts to decrease.

Accepted Answer

As more resistors are added in series, the total resistance of the circuit increases. According to Ohm's Law, if the resistance increases, the current flowing in the circuit decreases. Since power is calculated as P=VI, if current decreases the power will also decrease, so the power supplied by the source will decrease.

Question 9

The lamps in a string of decorative lights are connected in parallel across a constant-voltage power source.What happens if one lamp burns out? (Assume negligible resistance in the wires leading to the lamps. )
A)The brightness of the lamps will not change appreciably.
B)The other lamps get brighter equally.
C)The other lamps get brighter,but some get brighter than others.
D)The other lamps get dimmer equally.
E)The other lamps get dimmer,but some get dimmer than others.

Accepted Answer

In a parallel circuit, each lamp operates independently of the others. If one lamp burns out, the voltage across the remaining lamps does not change, so their brightness remains the same.

Question 10

When unequal resistors are connected in parallel in a circuit,
A)the same current always runs through each resistor.
B)the potential drop is always the same across each resistor.
C)the largest resistance has the largest current through it.
D)the power generated in each resistor is the same.

Accepted Answer

In a parallel circuit, the voltage across each component is the same, regardless of the resistance of each component.

Question 11

When two or more different capacitors are connected in series across a potential source,which of the following statements must be true? (There could be more than one correct choice. )
A)The total voltage across the combination is the algebraic sum of the voltages across the individual capacitors.
B)Each capacitor carries the same amount of charge.
C)The equivalent capacitance of the combination is less than the capacitance of any of the capacitors.
D)The potential difference across each capacitor is the same.
E)The capacitor with the largest capacitance has the most charge.

Accepted Answer

A) When capacitors are connected in series, the total voltage across the combination is indeed the algebraic sum of the voltages across each capacitor. This is because the voltage drop across each component adds up to the total voltage supplied by the source.B) In a series circuit, the same charge passes through each capacitor. This is because charge cannot accumulate at any point in the circuit without creating an equal and opposite charge somewhere else in the circuit, leading to a uniform charge distribution across all capacitors.C) The equivalent capacitance of capacitors in series is less than the smallest individual capacitor's capacitance. This is because the inverse of the total capacitance is the sum of the inverses of the individual capacitances, leading to a smaller equivalent capacitance.

Question 12

For the graph shown in the figure,what physical quantity does the slope of the graph represent for a dc circuit? A)1/(resistance) B)resistance C)potential D)(potential)² E)1/(potential)

Accepted Answer

The answer of For the graph shown in the figure,what...

Question 13

A 5-µF,a 7-µF,and an unknown capacitor C_X are connected in series between points a and b.What do you know about the equivalent capacitance C_ab between a and b? (There could be more than one correct choice. ) A)C_ab > 12 µF B)5 µF < C_ab < 7 µF C)5 µF < C_ab < 12 µF D)C_ab < 5 µF E)C_ab < C_X

Accepted Answer

When capacitors are connected in series, the equivalent capacitance is always less than the smallest individual capacitor in the series. Therefore, the equivalent capacitance must be less than 5 µF, making D correct. Additionally, the equivalent capacitance of a series combination is always less than any individual capacitor in that series, making E correct as well.

Question 14

For the graph shown in the figure,what physical quantity does the slope of the graph represent for a dc circuit? A)1/(resistance) B)resistance C)potential D)(potential)² E)1/(potential)

Accepted Answer

The answer of For the graph shown in the figure,what...

Question 15

For the graph shown in the figure,what physical quantity does the slope of the graph represent for a dc circuit? 
A)1/(current)
B)resistance
C)1/(resistance)
D)current
E)resistivity

Accepted Answer

The answer of For the graph shown in the figure,what...

Question 16

When unequal resistors are connected in series across an ideal battery,
A)the same power is dissipated in each one.
B)the potential difference across each is the same.
C)the current flowing in each is the same.
D)the equivalent resistance of the circuit is less than that of the smallest resistor.
E)the equivalent resistance of the circuit is equal to the average of all the resistances.

Accepted Answer

When resistors are connected in series, the same current flows through each resistor, regardless of their individual resistances. This is because there is only one path for the current to flow through the circuit.

Question 17

When two or more different capacitors are connected in parallel across a potential source (battery),which of the following statements must be true? (There could be more than one correct choice. )
A)The potential difference across each capacitor is the same.
B)Each capacitor carries the same amount of charge.
C)The equivalent capacitance of the combination is less than the capacitance of any one of the capacitors.
D)The capacitor with the largest capacitance has the largest potential difference across it.
E)The capacitor with the largest capacitance has the most charge.

Accepted Answer

When capacitors are connected in parallel, they all experience the same potential difference as that of the source. The charge stored in each capacitor is determined by its capacitance and the common voltage across them, with the capacitor having the largest capacitance storing the most charge.

Question 18

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?
A)3Q
B)Q
C)Q/3
D)Q/9

Accepted Answer

In a series circuit, the charge on each capacitor is the same as the charge that flows into the circuit. Therefore, each capacitor carries a charge of Q.

Question 19

Four unequal resistors are connected in a parallel with each other.Which one of the following statements is correct about this combination?
A)The equivalent resistance is less than that of the smallest resistor.
B)The equivalent resistance is equal to the average of the four resistances.
C)The equivalent resistance is midway between the largest and smallest resistance.
D)The equivalent resistance is more than the largest resistance.
E)None of the other choices is correct.

Accepted Answer

When resistors are connected in parallel, the equivalent resistance is less than the smallest resistor in the combination. This is because the total conductance (inverse of resistance) of the circuit increases with each additional resistor, leading to a lower overall resistance.

Question 20

When different resistors are connected in parallel across an ideal battery,we can be certain that
A)the same current flows in each one.
B)the potential difference across each is the same.
C)the power dissipated in each is the same.
D)their equivalent resistance is greater than the resistance of any one of the individual resistances.
E)their equivalent resistance is equal to the average of the individual resistances.

Accepted Answer

According to Ohm's Law, the potential difference (voltage) across each resistor in a parallel circuit is the same as the voltage of the battery. Therefore, choice B is correct. The current flowing through each resistor will depend on the individual resistance values, so choice A is incorrect. The power dissipated in each resistor will depend on the individual resistance values and the current flowing through them, so choice C is also incorrect. The equivalent resistance of resistors in parallel is always less than the resistance of any one of the individual resistances, so choice D is incorrect. Choice E is also incorrect as it suggests that the equivalent resistance is a simple average value, which is not the case for resistors in parallel.

Quiz 21: Electric Current and Direct-Current Circuits

A 5-µF,a 7-µF,and an unknown capacitor C_X are connected in parallel between points a and b as shown in the figure.What do you know about the equivalent capacitance C_ab between a and b? (There could be more than one correct choice. )

Suppose you have two capacitors and want to use them to store the maximum amount of energy by connecting them across a voltage source.You should connect them

You obtain a 100-W light bulb and a 50-W light bulb.Instead of connecting them in the normal way,you devise a circuit that places them in series across normal household voltage.If each one is an incandescent bulb of fixed resistance,which statement about these bulbs is correct?

Four unequal resistors are connected in series with each other.Which one of the following statements is correct about this combination?

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?

As more resistors are added in parallel across a constant voltage source,the power supplied by the source

As more resistors are added in series to a constant voltage source,the power supplied by the source

The lamps in a string of decorative lights are connected in parallel across a constant-voltage power source.What happens if one lamp burns out? (Assume negligible resistance in the wires leading to the lamps. )

When unequal resistors are connected in parallel in a circuit,

When two or more different capacitors are connected in series across a potential source,which of the following statements must be true? (There could be more than one correct choice. )

For the graph shown in the figure,what physical quantity does the slope of the graph represent for a dc circuit?

A 5-µF,a 7-µF,and an unknown capacitor C_X are connected in series between points a and b.What do you know about the equivalent capacitance C_ab between a and b? (There could be more than one correct choice. )

For the graph shown in the figure,what physical quantity does the slope of the graph represent for a dc circuit?

For the graph shown in the figure,what physical quantity does the slope of the graph represent for a dc circuit?

When unequal resistors are connected in series across an ideal battery,

When two or more different capacitors are connected in parallel across a potential source (battery) ,which of the following statements must be true? (There could be more than one correct choice. )

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?

Four unequal resistors are connected in a parallel with each other.Which one of the following statements is correct about this combination?

When different resistors are connected in parallel across an ideal battery,we can be certain that

Quiz 21: Electric Current and Direct-Current Circuits

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? (There could be more than one correct choice. )

Suppose you have two capacitors and want to use them to store the maximum amount of energy by connecting them across a voltage source.You should connect them

You obtain a 100-W light bulb and a 50-W light bulb.Instead of connecting them in the normal way,you devise a circuit that places them in series across normal household voltage.If each one is an incandescent bulb of fixed resistance,which statement about these bulbs is correct?

Four unequal resistors are connected in series with each other.Which one of the following statements is correct about this combination?

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?

As more resistors are added in parallel across a constant voltage source,the power supplied by the source

As more resistors are added in series to a constant voltage source,the power supplied by the source

The lamps in a string of decorative lights are connected in parallel across a constant-voltage power source.What happens if one lamp burns out? (Assume negligible resistance in the wires leading to the lamps. )

When unequal resistors are connected in parallel in a circuit,

When two or more different capacitors are connected in series across a potential source,which of the following statements must be true? (There could be more than one correct choice. )

For the graph shown in the figure,what physical quantity does the slope of the graph represent for a dc circuit?

A 5-µF,a 7-µF,and an unknown capacitor CX are connected in series between points a and b.What do you know about the equivalent capacitance Cab between a and b? (There could be more than one correct choice. )

For the graph shown in the figure,what physical quantity does the slope of the graph represent for a dc circuit?

For the graph shown in the figure,what physical quantity does the slope of the graph represent for a dc circuit?

When unequal resistors are connected in series across an ideal battery,

When two or more different capacitors are connected in parallel across a potential source (battery) ,which of the following statements must be true? (There could be more than one correct choice. )

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?

Four unequal resistors are connected in a parallel with each other.Which one of the following statements is correct about this combination?

When different resistors are connected in parallel across an ideal battery,we can be certain that

A 5-µF,a 7-µF,and an unknown capacitor C_X are connected in parallel between points a and b as shown in the figure.What do you know about the equivalent capacitance C_ab between a and b? (There could be more than one correct choice. )

A 5-µF,a 7-µF,and an unknown capacitor C_X are connected in series between points a and b.What do you know about the equivalent capacitance C_ab between a and b? (There could be more than one correct choice. )