Question 1

Two unknown resistors are connected together.When they are connected in series their equivalent resistance is 15 Ω.When they are connected in parallel,their equivalent resistance is 3.3 Ω.What are the resistances of these resistors?

Accepted Answer

4.9 Ω and 10 Ω

Question 2

A galvanometer G has an internal resistance r_g.An AMMETER is constructed by incorporating the galvanometer and an additional resistance R_s.Which one of the figures below is the most appropriate circuit diagram for the ammeter? A) 1 B) 2 C) 3 D) 4 E) 5

Accepted Answer

D

Question 3

A galvanometer G has an internal resistance r_g.A VOLTMETER is constructed by incorporating the galvanometer and an additional resistance R_s.Which one of the figures below is the most appropriate circuit diagram for the voltmeter? A) 1 B) 2 C) 3 D) 4 E) 5

Accepted Answer

A

Question 4

A light bulb is connected in the circuit shown in the figure with the switch S open.All the connecting leads have no appreciable resistance and the battery has no internal resistance.When we close the switch,which statements below accurately describe the behavior of the circuit? (There may be more than one correct choice.) A) The brightness of the bulb will increase. B) The brightness of the bulb will decrease. C) The brightness of the bulb will not change. D) The potential drop across R₂ will decrease. E) The potential drop across R₂ will not change.

Accepted Answer

The answer of A light bulb is connected in the...

Question 5

Two light bulbs,B₁ and B₂,are connected to a battery having appreciable internal resistance as shown in the figure.What happens to the brightness of bulb B₁ when we close the switch S? A) The brightness of B₁ increases permanently. B) The brightness of B₁ decreases permanently. C) The brightness of B₁ does not change. D) The brightness of B₁ increases temporarily but gradually decreases back to its original brightness. E) The brightness of B₁ decreases temporarily but gradually increases back to its original brightness.

Accepted Answer

The answer of Two light bulbs,B₁ and B₂,are connected to...

Question 6

In the circuit shown in the figure,four identical resistors labeled A to D are connected to a battery as shown.S₁ and S₂ are switches.Which of the following actions would result in the GREATEST amount of current through resistor A? A) closing both switches B) closing S₁ only C) closing S₂ only D) leaving both switches open as shown

Accepted Answer

The answer of In the circuit shown in the figure,four...

Question 7

Four resistors are connected across an 8-V DC battery as shown in the figure.The current through the 9-Ω resistor is closest to 
A) 1 A.
B) 0.7 A.
C) 0.5 A.
D) 0.9 A.
E) 2 A.

Accepted Answer

To find the current through the 9-Ω resistor, we can use Ohm's Law, which states that V = IR, where V is the voltage, I is the current, and R is the resistance.

First, we can find the equivalent resistance of the circuit using the formula:

Req = R1 + R2 || R3 + R4

where || represents a parallel combination.

Using this formula:

Req = 6 + 4 || 8 + 9 
Req = 6 + 2.3 + 8 
Req = 16.3 Ω

Now we can use Ohm's Law to find the current I:

I = V / Req 
I = 8 / 16.3 
I ≈ 0.49 A

This means that the current through the 9-Ω resistor is closest to 0.7 A (since it is in parallel with the 8-Ω resistor, which has the same voltage drop and thus the same current). Therefore, the best choice is B.

Question 8

A resistor is made out of a long wire having a length L.Each end of the wire is attached to a terminal of a battery providing a constant voltage V₀.A current I flows through the wire.If the wire were cut in half,making two wires of length L/2,and both wires were attached to the battery (the end of both wires attached to one terminal,and the other ends attached to the other terminal),what would be the total current flowing through the two wires? A) 4I B) 2I C) I D) I/2 E) I/4

Accepted Answer

When the wire is cut in half and both halves are connected in parallel to the battery, the resistance of each half is halved. Since the wires are in parallel, the total resistance is further reduced by half, resulting in a total resistance of one-fourth of the original. According to Ohm's Law (V = IR), the current is inversely proportional to the resistance, so the total current becomes four times the original current, 4I.

Question 9

Thirteen resistors are connected across points A and B as shown in the figure.If all the resistors are accurate to 2 significant figures,what is the equivalent resistance between points A and B? 
A) 4.0 Ω
B) 6.0 Ω
C) 8.0 Ω
D) 10 Ω
E) 12 Ω

Accepted Answer

The answer of Thirteen resistors are connected across points A...

Question 10

A 4.00-Ω resistor,an 8.00-Ω resistor,and a 24.0-Ω resistor are connected together.
(a)What is the maximum resistance that can be produced using all three resistors?
(b)What is the minimum resistance that can be produced using all three resistors?
(c)How would you connect these three resistors to obtain a resistance of 10.0 Ω?
(d)How would you connect these three resistors to obtain a resistance of 8.00 Ω?

Accepted Answer

The answer of A 4.00-Ω resistor,an 8.00-Ω resistor,and a 24.0-Ω...

Question 11

For the circuit shown in the figure,determine the current in
(a)the 1.0-Ω resistor.
(b)the 3.0-Ω resistor.
(c)the 4.0-Ω resistor.

Accepted Answer

The answer of For the circuit shown in the figure,determine...

Question 12

An RC circuit is connected across an ideal DC voltage source through an open switch.The switch is closed at time t = 0 s.Which of the following statements regarding the circuit are correct? (There may be more than one correct choice.)
A) The capacitor charges to its maximum value in one time constant and the current is zero at that time.
B) The potential difference across the resistor and the potential difference across the capacitor are always equal.
C) The potential difference across the resistor is always greater than the potential difference across the capacitor.
D) The potential difference across the capacitor is always greater than the potential difference across the resistor
E) Once the capacitor is essentially fully charged, there is no appreciable current in the circuit.

Accepted Answer

Once the capacitor is fully charged, it acts like an open circuit, and the current in the circuit becomes negligible.

Question 13

A light bulb is connected in the circuit shown in the figure with the switch S open and the capacitor uncharged.The battery has no appreciable internal resistance.Which one of the following graphs best describes the brightness B of the bulb as a function of time t after closing the switch?  
A) 1
B) 2
C) 3
D) 4
E) 5

Accepted Answer

The answer of A light bulb is connected in the...

Question 14

Three resistors are connected across an ideal 2.0-V DC battery as shown in the figure.
(a)At what rate does the battery supply energy to the resistors?
(b)At what rate is heat produced in the 6.0-Ω resistor?

Accepted Answer

The answer of Three resistors are connected across an ideal...

Question 15

The figure shows three identical lightbulbs connected to a battery having a constant voltage across its terminals.What happens to the brightness of lightbulb 1 when the switch S is closed? 
A) The brightness will increase momentarily then return to its previous level.
B) The brightness increases permanently.
C) The brightness will decrease momentarily then return to its previous level.
D) The brightness remains the same as before the switch is closed.
E) The brightness decreases permanently.

Accepted Answer

The answer of The figure shows three identical lightbulbs connected...

Question 16

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.

Accepted Answer

When more resistors are added in parallel across a constant voltage source, the total circuit resistance 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), an increase in current results in an increase in the power supplied by the source.

Question 17

Three resistors having resistances of 4.0 Ω,6.0 Ω,and 10.0 Ω are connected in parallel.If the combination is connected in series with an ideal 12-V battery and a 2.0-Ω resistor,what is the current through the 10.0-Ω resistor?
A) 0.59 A
B) 2.7 A
C) 6.4 A
D) 11.2 A
E) 16 A

Accepted Answer

When resistors are connected in parallel, the total equivalent resistance is given by:

1/R = 1/R1 + 1/R2 + 1/R3
1/R = 1/4 + 1/6 + 1/10
1/R = 15/120
R = 8 Ω

The current passing through this parallel combination when connected to a 12-V battery can be calculated using Ohm's law:

I = V/R
I = 12/8
I = 1.5 A

Now, when this combination is connected in series with a 2-Ω resistor, the total equivalent resistance is:

R = 8 + 2
R = 10 Ω

The current passing through the resistance of 10 Ω can be calculated using Ohm's law:

I = V/R
I = 12/10
I = 1.2 A

Therefore, the current through the 10.0-Ω resistor is 1.2 A (choice A).

Question 18

In the circuit shown in the figure,an ideal ohmmeter is connected across ab with the switch S open.All the connecting leads have negligible resistance.The reading of the ohmmeter will be closest to 
A) 7.5 Ω.
B) 10 Ω.
C) 30 Ω.
D) 40 Ω.
E) 60 Ω.

Accepted Answer

The answer of In the circuit shown in the figure,an...

Question 19

In the circuit shown in the figure,all the lightbulbs are identical.Which of the following is the correct ranking of the brightness of the bulbs? 
A) B and C have equal brightness, and A is the dimmest.
B) A and B have equal brightness, and C is the dimmest.
C) A is brightest, C is dimmest, and B is in between.
D) A is the brightest, and B and C have equal brightness but less than A.
E) All three bulbs have the same brightness.

Accepted Answer

The answer of In the circuit shown in the figure,all...

Question 20

A 5.0-Ω resistor and a 9.0-Ω resistor are connected in parallel.A 4.0-Ω resistor is then connected in series with this parallel combination.An ideal 6.0-V battery is then connected across the series-parallel combination of the three resistors.What is the current through
(a)the 4.0-Ω resistor?
(b)the 5.0-Ω resistor?
(c)the 9.0-Ω resistor?

Accepted Answer

The answer of A 5.0-Ω resistor and a 9.0-Ω resistor...

Quiz 26: Direct-Current Circuits

Two unknown resistors are connected together.When they are connected in series their equivalent resistance is 15 Ω.When they are connected in parallel,their equivalent resistance is 3.3 Ω.What are the resistances of these resistors?

A galvanometer G has an internal resistance rg.An AMMETER is constructed by incorporating the galvanometer and an additional resistance Rs.Which one of the figures below is the most appropriate circuit diagram for the ammeter?

A galvanometer G has an internal resistance rg.A VOLTMETER is constructed by incorporating the galvanometer and an additional resistance Rs.Which one of the figures below is the most appropriate circuit diagram for the voltmeter?

Two light bulbs,B1 and B2,are connected to a battery having appreciable internal resistance as shown in the figure.What happens to the brightness of bulb B1 when we close the switch S?

In the circuit shown in the figure,four identical resistors labeled A to D are connected to a battery as shown.S1 and S2 are switches.Which of the following actions would result in the GREATEST amount of current through resistor A?

Four resistors are connected across an 8-V DC battery as shown in the figure.The current through the 9-Ω resistor is closest to

Thirteen resistors are connected across points A and B as shown in the figure.If all the resistors are accurate to 2 significant figures,what is the equivalent resistance between points A and B?

For the circuit shown in the figure,determine the current in (a)the 1.0-Ω resistor. (b)the 3.0-Ω resistor. (c)the 4.0-Ω resistor.

An RC circuit is connected across an ideal DC voltage source through an open switch.The switch is closed at time t = 0 s.Which of the following statements regarding the circuit are correct? (There may be more than one correct choice.)

A light bulb is connected in the circuit shown in the figure with the switch S open and the capacitor uncharged.The battery has no appreciable internal resistance.Which one of the following graphs best describes the brightness B of the bulb as a function of time t after closing the switch?

Three resistors are connected across an ideal 2.0-V DC battery as shown in the figure. (a)At what rate does the battery supply energy to the resistors? (b)At what rate is heat produced in the 6.0-Ω resistor?

The figure shows three identical lightbulbs connected to a battery having a constant voltage across its terminals.What happens to the brightness of lightbulb 1 when the switch S is closed?

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

Three resistors having resistances of 4.0 Ω,6.0 Ω,and 10.0 Ω are connected in parallel.If the combination is connected in series with an ideal 12-V battery and a 2.0-Ω resistor,what is the current through the 10.0-Ω resistor?

In the circuit shown in the figure,an ideal ohmmeter is connected across ab with the switch S open.All the connecting leads have negligible resistance.The reading of the ohmmeter will be closest to

In the circuit shown in the figure,all the lightbulbs are identical.Which of the following is the correct ranking of the brightness of the bulbs?

A galvanometer G has an internal resistance r_g.An AMMETER is constructed by incorporating the galvanometer and an additional resistance R_s.Which one of the figures below is the most appropriate circuit diagram for the ammeter?

A galvanometer G has an internal resistance r_g.A VOLTMETER is constructed by incorporating the galvanometer and an additional resistance R_s.Which one of the figures below is the most appropriate circuit diagram for the voltmeter?

Two light bulbs,B₁ and B₂,are connected to a battery having appreciable internal resistance as shown in the figure.What happens to the brightness of bulb B₁ when we close the switch S?

In the circuit shown in the figure,four identical resistors labeled A to D are connected to a battery as shown.S₁ and S₂ are switches.Which of the following actions would result in the GREATEST amount of current through resistor A?