Tags

There are 85 questions tagged under Circuits.

1

### Q:

You are given three 2-ohm resistors. How many different total resistances can be produced if all three resistors are used in a circuit?

2

3

4

5

Tags: Circuits |

2

### Q:

Three resistors are in parallel in a circuit. One has a resistance 3 ohms, another 2 ohms, and the third is unknown. If the effective resistance of the circuit is 1 ohm, what is the resistance of the unknown resistor?

7 ohms

6 ohms

1/6 ohms

5 ohms

Tags: Circuits |

3

### Q:

You are given three capacitors of capacitance X. If you are allowed to place the capacitors in a circuit in any fashion, how many different effective capacitances can you get?

1

2

3

### D

4

Tags: Circuits | Quantitative Skills |

4

### Q:

You are given three capacitors, each of capacitance 5 farads. Which of the following capacitances could not be derived through placing the capacitors in any permutation of in parallel or in series in a circuit. Assume a constant voltage.

15 F

7.5 F

3.5 F

1.7 F

Tags: Circuits |

5

### Q:

Dr. Frankenstein is attempting to run a current through his human creation and give it life. The creation acts as a resistor of resistance 5 ohms, in parallel with a resistor of resistance 1.25 ohms. Dr. Frankenstein calculates that the creation can absorb 100 W before overheating and ruining the experiment. What is the maximal voltage that Dr. Frankenstein can administer?

10V

25V

100V

625V

Tags: Circuits |

6

### Q:

A battery of 30 V is attached to two resistors in parallel. The resistors have resistances x and y. If the current through the resistor with resistance x is 15 A, what is the voltage across the resistor with resistance y?

15 V

30 V

45 V

0 V

Tags: Circuits |

7

### Q:

A capacitor is placed in a circuit containing a 9 V battery. The capacitor is composed of two circular metal sheets of radius R separated by a distance D. If R is doubled and D is halved, what is the effect on capacitance?

### A

Increases 8 times

### B

Increases 4 times

### C

Increases 2 times

Remains constant

Tags: Circuits |

8

### Q:

A cylindrical resistor has resistance R. If its resistivity is tripled while its cross-sectional radius is doubled, what is the resistance of the final resistor?

3R/4

4R/3

3R/2

2R/3

Tags: Circuits |

9

### Q:

A capacitor is placed in series with a resistor and as well as a battery with voltage V. What is the behavior of the current through the circuit with respect to time?

### A

Current remains constant over time

### B

Current increases over time until it reaches a maximal level

### C

Current decreases over time and eventually reaches zero.

### D

Current increases initially, and then decreases to zero.

Tags: Circuits |

10

### Q:

Which of the following statements regarding resistance is true?

### A

Temperature does not affect the resistance of a material.

### B

Passing a current through a wire with nonzero resistance results in the generation of heat.

### C

Conductors do not have resistance.

### D

The resistance of a wire is proportional to the inverse square of its length.

Tags: Circuits |

11

### Q:

The current through a circuit is 0.3 A while its resistance is 30 Ω. What is the voltage supplied by the battery in the circuit?

3 V

6 V

9 V

90 V

Tags: Circuits |

12

### Q:

A resistor is placed in a circuit with a battery of voltage V. The resistance of the resistor is R. If the resistor is replaced with a resistor with twice the diameter, twice the length, and the voltage is doubled, what is the new resistance of the resistor?

8R

4R

R/4

R/2

Tags: Circuits |

13

### Q:

Three capacitors with capacitance of 2 F, 4 F, and 8 F can be arranged in any way within a circuit. What is the maximum capacitance achievable by the three capacitors?

7/8 F

8 F

8.75 F

14 F

Tags: Circuits |

14

### Q:

Which of the following units is not a function of time?

Velocity

Power

### C

Electrical Conductivity

### D

Energy

Tags: Kinematics | Energy & Work | Circuits |

15

### Q:

A capacitor is placed in a circuit containing a 13 V battery. The capacitor is composed of two circular metal sheets of radius R separated by a distance D. If R is doubled and D is halved, what is the effect on capacitance?

Remains constant

### B

Increases 2 times

### C

Increases 4 times

### D

Increases 8 times

Tags: Circuits | Magnetism |

16

### Q:

A circular parallel plate capacitor has capacitance C. Another similarly-shaped capacitor with a radius twice that of the first capacitor will have capacitance

C/2

2C

C2

### D

None of the above

Tags: Circuits |

17

### Q:

Which of the following resistors must be placed in series with a 10 Ω, 20 Ω, and 50 Ω resistor in order to create a total resistance of 100 Ω in the circuit?

1/20 Ω

1/19.83 Ω

19.83 Ω

20 Ω

Tags: Circuits |

18

### Q:

The resistance of a wire is dependent upon the length of the wire and its cross-sectional area. The relationship between the resistance and the length (l) and cross sectional area (A) is

l * A

l / A

l - A

l + A

Tags: Circuits |

19

### Q:

Biologists often view the membrane of a neuron as a capacitor, because it separates charged ions inside and outside the membrane. Which of the following changes to the membrane would allow for increased ability of the membrane to separate charge?

### A

Longer fatty acid chains in the phospholipid membrane.

### B

Shortening the fatty acid chains in the phospholipid membrane.

### C

Inserting magnesium ion symporters in the membrane.

### D

None of the above

Tags: Membrane Transport and Signalling | Circuits |

20

### Q:

A resistor, with resistance 3.0 ohms, is placed in parallel to the 3.0 ohm light bulb (Circuit A → Circuit B). What happens to the brightness of the light bulb?

### A

It becomes brighter.

### B

No change in brightness.

### C

It becomes dimmer.

### D

No light is emitted.

Tags: Circuits |

21

### Q:

Three capacitors are lined in parallel. The respective capacitance values are 1 F, 2 F and 3 F. What is the effective capacitance of the three capacitors?

5 F

6 F

11/6 F

### D

5/6 F

Tags: Circuits | Quantitative Skills |

22

### Q:

The energy stored in a capacitor is 60 J. The circuit voltage is 2 volts. What is the capacitance of the capacitor?

15 F

30 F

60 F

### D

120 F

Tags: Circuits | Quantitative Skills |

23

### Q:

There are two resistors, each 0.5 Ohm, in series in a circuit. The power from the circuit can be used by a machine to lift a mass of 40 kg up 1 meter in a second. What is the current running through the circuit?

5 amperes

10 amperes

15 amperes

### D

20 amperes

Tags: Circuits | Quantitative Skills |

24

### Q:

The energy stored in a capacitor is 100 kJ. The capacitance of the capacitor is equal to 0.02 F. What is the charge that can be held in the capacitor?

5 C

10 C

63 C

### D

20 C

Tags: Circuits | Quantitative Skills |

25

### Q:

There is a 6V circuit with a 2Ω resistor followed in series by two more 2Ω resistors (which are parallel to each other). What is the current running through this circuit?

1 A

2 A

4 A

### D

0.5 A

Tags: Quantitative Skills | Circuits |

26

### Q:

There is a stationary rectangular loop circuit. A magnetic field passes through the loop and into the page. The magnetic field is increasing. What is the direction of the induced current?

Clockwise

### B

Counter-clockwise

### C

There is no induced current.

### D

There is not enough information to determine the direction of the induced current.

Tags: Circuits |

27

### Q:

Which of the following statements is false?

### A

Resistors impede the free motion of electrons

### B

Conductors can be charged by induction

### C

The area under a charge vs. voltage graph for a capacitor gives the energy stored in the capacitor.

### D

Kirchoff's first rule states that the voltage entering a junction will be equally divided between the two resistors of a parallel circuit.

Tags: Circuits |

28

### Q:

A circuit contains two capacitors in series. Their capacitance is R and Q where R < Q. Which of the following is true about the capacitance C of the circuit?

C = R + Q

C < R

R < C < Q

### D

1/C = R + Q

Tags: Circuits | Quantitative Skills |

29

### Q:

Three resistors, each of resistance X, are provided to a student. Which of the following is not a possible resistance of a circuit made with these resistors (assuming that the resistors can be placed in various combinations of parallel/series)?

4X/3

3X

2X/3

X/3

Tags: Circuits |

30

### Q:

A 2-foot-by-2-foot square plate capacitor is used to store electrical energy for a science project. Plates are separated by a distance of 0.25 inches. Which of the following does not hold true regarding this set up?

### A

Changing distance between the plates to 0.5 inches will decrease capacitance

### B

Capacitance is proportional to the total charge separated by the plates

### C

Replacing the plates with circular plates of radius 1 foot will decrease the capacitance

### D

All of the above hold true

Tags: Circuits |

31

### Q:

A metal ion (X+) is found to undergo an electrolytic reaction to become X with an electric potential of 2.5 V. The molar mass of X is M. A current of I is applied for a time t. Given that F is Faraday's constant, which of the following expressions correctly shows the mass of X that will be formed through the current?

MFIt

MFIt / 2.5

MIt/F

### D

MIt/(2.5 * F)

Tags: Circuits | Quantitative Skills |

32

### Q:

Which of the following statements must be true for resistors placed in parallel?

### A

The combined resistance is equal to the sum of each of the individual resistances.

### B

The combined resistance is less than any of the given individual resistors.

### C

The current will flow equally through each resistor.

### D

The current will flow only through the resistor with the lowest resistance.

Tags: Circuits |

33

### Q:

If a total of 2 x 1020 electrons flow at a constant rate through a wire over 5 seconds, what is the current in the wire? Note: 1 e- = 1.6 x 10-19 C.

1.5 A

6.4 A

32 A

### D

The answer cannot be determined from the given information.

Tags: Circuits | Quantitative Skills |

34

### Q:

Lead acid batteries, like those typically found in vehicles, are composed primarily of lead and sulfuric acid. An individual cell of the battery has a voltage of 2 V, but batteries for cars typically will have a voltage of 12 V. This increase in voltage can be accomplished in which of the following ways?

### A

placing the cells in series

### B

placing the cells in parallel

### C

adding more lead to the cells

### D

increasing the concentration of sulfuric acid in the cells

Tags: Circuits |

35

### Q:

Six volts are required to power the lightbulb in the circuit diagram below (Item 1). With two 3-V batteries, which of the following circuits would deliver the desired voltage?

Tags: Circuits |

36

### Q:

As the plate surface area of a parallel-plate capacitor rises, its capacitance will do which of the following?

### A

Increase linearly

### B

Increase proportional to the square of the surface area

### C

Decrease linearly

### D

Decrease proportional to the square of the surface area

Tags: Circuits |

37

### Q:

The valence band is the range of electronic states where electrons can exist for an atom in their ground state. The conduction band refers to the energy states that will allow for the delocalization of electrons for conduction. A large band gap - the distance between the conduction band and the valence band - would have a direct impact on which of the following?

### A

the resistivity of the material

### B

the capacitance of the material

### C

the ionization energy of the material

### D

the reactivity of the material

Tags: Circuits |

38

### Q:

Voltmeters are built to have resistances as near to infinity as possible. For a circuit with a voltmeter attached in parallel to given circuit element, which of the following is true?

### A

The voltage across the voltmeter is close to zero.

### B

The current passing through the voltmeter is close to zero.

### C

The voltage across the voltmeter is close to infinity.

### D

The current passing through the voltmeter is close to infinity.

Tags: Circuits |

39

### Q:

If the charge on a capacitor is doubled with a doubling of the voltage, the capacitance of the capacitor:

is halved

remains the same

is doubled

is quadrupled

Tags: Circuits |

40

### Q:

A student wants to increase the speed of a motor by increasing the voltage. After an adjustment, the student connects a second battery in parallel to the first battery to drive the motor. Will this setup achieve the desired effect?

### A

Yes, because the two batteries double the voltage.

### B

Yes, because the two batteries double the current.

### C

No, because the two batteries do not change the voltage.

### D

No, because the two batteries do not change the current.

Tags: Circuits |

41

### Q:

A variable resistor is able to have its resistance altered without needing to be disconnected from a circuit. If a constant 5 amps of current are run through a circuit while the resistance is increased, what will happen to the voltage of the circuit?

### A

The voltage will decrease.

### B

The voltage will not change.

### C

The voltage will increase.

### D

The answer cannot be determined with the given information.

Tags: Circuits | Quantitative Skills |

42

### Q:

Superconducting materials can pass current very efficiently and have a resistance of 0 Ω and therefore no voltage can be measured across a superconductor itself even when passing a current. If a superconducting wire were connected to a battery, the resistance of the circuit would be:

equal to 0.

### B

equal to the voltage of the battery.

### C

equal to the internal resistance of the battery.

### D

undefined; the battery cannot pass current through the superconductor.

Tags: Circuits |

43

### Q:

A lithium-ion cell has a potential of 3 V. A 9-volt lithium-ion battery can be created by which of the following?

### A

Arranging three cells in parallel

### B

Arranging three cells in series

### C

Increasing the concentration of the lithium ions by a factor of three

### D

Decreasing the resistance of the circuit by a factor of three

Tags: Circuits |

44

### Q:

Using only three resistors with resistances of 1 Ω, 2 Ω, and 3 Ω, what is the maximum resistance that can be created in a circuit?

1.5 Ω

8/6 Ω

6 Ω

### D

9 Ω

Tags: Circuits | Quantitative Skills |

45

### Q:

A resistor is rated to consume 100 W of power when operating at its normal temperature. When it is first initiated, it is cold, and power consumption increases linearly as the temperature rises. If the current passing through the resistor is constant, how does the resistance of the resistor change with the linearly-increasing power?

### A

The resistance increases linearly.

### B

The resistance decreases linearly.

### C

The resistance increases exponentially.

### D

The resistance decreases exponentially.

Tags: Circuits |

46

### Q:

Which of the following would increase the resistance of a closed-circuit system?

I. Replacing the wire with one of the same material that has a smaller cross sectional area
II. Adding a voltmeter to the circuit in series.
III. Doubling the wire length in the closed circuit.

II only

I and III only

II and III only

I, II, and III

Tags: Circuits |

47

### Q:

What is the maximum capacitance that can be created on a circuit with 3 capacitors with capacitance of 1 μF, 2 μF, and 4 μF?

0.57 μF

4 μF

7 μF

### D

8 μF

Tags: Circuits | Quantitative Skills |

48

### Q:

Which of the following provides a plausible explanation for why resistance of resistors add when they are in series rather than in parallel?

### A

Total resistance of a set of resistors has no relation to the length of the resistor, thus it is intuitive that adding in series is most accurate for adding resistors

### B

Increased area of a resistor increases its resistance, and adding resistors in series functionally increases cross-sectional area

### C

Resistors in parallel increase distance that current must travel, thus it is intuitive that this would decrease resistance (and resistors in series would add resistance)

### D

Increased length of a resistor increases its resistance and adding resistors in series is functionally equivalent to adding length to the resistor

Tags: Circuits |

49

### Q:

A capacitor is connected in series with a battery. During the initial moments when a potential is accumulated across the capacitor, which of the following is true of electron motion?

### A

Electrons move from the plate of the capacitor closest to the (+) side of the battery to the other to create a potential difference

### B

Electrons move from the plate of the capacitor closest to the (-) side of the battery to the other to create a potential difference

### C

Zero electrons move in between the plates

### D

Potential difference across the plates is monotonically decreasing with increasing time

Tags: Circuits |

50

### Q:

Three capacitors are in series in a circuit. One with a capacitance of 3 farads, one with 2 farads, and one unknown. If the total capacitance is 1 farad, what is the capacitance of the third capacitor?

1 farad

2 farads

3 farads

### D

6 farads

Tags: Circuits | Quantitative Skills |

51

### Q:

Which of the following variables is not a component of the equation for resistivity of a substance?

### A

length of the substance

### B

cross-sectional area of the substance

### C

resistance of the substance

### D

density of the substance

Tags: Circuits |

52

### Q:

The graph of a capacitor in a circuit discharging is most similar to which of the following graphs?

### A

A graph of velocity vs time of a racecar decellerating at a constant rate

### B

A graph of displacement vs time of a runner who makes one revolution around a circular track

### C

A graph of power vs current in a circuit with constant voltage

### D

Potential energy vs time of a spring which is released from a stretched position and returns to a state of zero displacement

Tags: Energy & Work | Circuits |

53

### Q:

What is the average voltage for alternating current (AC)?

>0 V

<0 V

0 V

### D

The voltage relates to the device attached to the circuit

Tags: Circuits |

54

### Q:

N resistors which have the resistance X are all connected in parallel and resistance is measured. This resistance comes out to R. What would the resistance be if these resistors were connected in series?

N2R

NR

N/R

1/NR

Tags: Circuits |

55

### Q:

Given two identical resistors in series, what is the current in the second resistor if there is an electric current through the two resistors?

### A

Equal to the current in the first resistor

### B

Twice the current of the first resistor

### C

Half the current of the first resistor

Zero

Tags: Circuits |

56

### Q:

Given the parallel circuit shown, what is expected to occur to the total resistance between the two points as additional identical resistors are added?

### A

The total resistance between the two points stays the same

### B

The total resistance between the two points decreases

### C

The total resistance between the two points increases by 1x as each resistor is added

### D

The total resistance between the two points increases by 2x as each resistor is added

Tags: Circuits |

57

### Q:

Given the following circuit, in which both light bulbs are identical, what will happen to the intensity of the bulbs if the circuit is closed?

### A

The intensities of both bulbs will increase by the same amount

### B

The intensities of both bulbs will decrease by the same amount

### C

Depending on the power, both bulbs will go out

### D

The intensities of both bulbs remain the same

Tags: Circuits |

58

### Q:

Given the two circuits below, and given that all the lightbulbs are the same, which will output more light?

### A

The left circuit, due to a smaller resistance of the two light bulbs

### B

The left circuit, due to a larger current going through the two light bulbs

### C

The right circuit, due to a smaller resistance of the two light bulbs

### D

The left and right circuit will output the same amount of light

Tags: Circuits |

59

### Q:

In the circuit below, each light bulb has a resistance of 20 Ω and the battery supplies a voltage of 20 V. How much power does Bulb 2 consume?

1 W

20 W

40 W

400 W

Tags: Circuits |

60

### Q:

Given the circuit below, which of the following statements about current is true?

### A

The current supplied by the battery long after the switch is closed is zero

### B

The current supplied by the battery long after the switch is closed is larger than the current supplied immediately after the switch is closed

### C

The current through the resistor R2 is largest immediately after the switch is closed

### D

The current supplied by the battery long after the switch is closed approaches a finite current which is smaller than the current supplied immediately after the switch is closed

Tags: Circuits |

61

### Q:

In the circuit below, a conductor is connected to a battery as shown. The conductor is in a magnetic field that is coming out of the page. If electrons are the charge carriers in this conductor, which of the following is true regarding the direction of the force that the electrons experience?

### A

The electrons do not experience a force from the magnetic field.

### B

The electrons experience a magnetic force into the page.

### C

The electrons experience a magnetic force out of the page.

### D

The electrons experience a magnetic force to the left.

Tags: Circuits | Electromagnetics |

62

### Q:

SDS-PAGE gels are often run at a constant voltage. Over time, however, the temperature of the medium rises and electrolytes are consumed, the current drawn:

increases.

decreases.

### C

remains constant.

is zero.

Tags: Circuits |

63

### Q:

What modification would decrease the resistance of a wire?

### A

Replacing the wire with a thinner one.

### B

Replacing the wire with a longer one.

### C

Replacing the wire with a metal that has a higher conductivity.

### D

Placing the wire in a conductive solution.

Tags: Circuits |

64

### Q:

A 12 V, 6,000 Amp-hour (Ah) battery can be drained by a motor in 4 hours. What is the average power drain of the motor?

2 kW

18 kW

8 kW

288 kW

Tags: Circuits |

65

### Q:

A transformer can "step up" voltage from one circuit to another through induction coils, without adding any extra energy to the circuit. A transformer can convert a circuit with 100 V and 20 A into 500,000 V and approximately how many amps?

0.004 A

4 A

20 A

100,000 A

Tags: Circuits |

66

### Q:

How would adding a battery in parallel affect a circuit?

### A

The voltage would increase.

### B

The voltage would decrease.

### C

The voltage would remain unchanged.

### D

The voltage would increase or decrease depending on the resistance of the circuit.

Tags: Circuits |

67

### Q:

Two resistors of resistance 3 Ohm are placed in series with each other and are then placed in parallel to a resistor also of resistance 3 Ohm. What is the overall resistance of this circuit?

2/3 Ohm

2 Ohm

5/3 Ohm

15/2 Ohm

Tags: Circuits |

68

### Q:

Which of the following is accurate regarding an ammeter?

### A

It typically has very low resistance.

### B

It is inserted in parallel in a circuit.

### C

It typically has very elevated resistance.

### D

It is used to measure voltage across a circuit.

Tags: Circuits |

69

### Q:

A potential of 100V is applied across capacitor plates which have a capacitance of 7 farads. Which of the following represents the energy stored in the capacitor?

700 J

4900 J

35,000 J

49,000 J

Tags: Circuits |

70

### Q:

A particular circuit is modified such that the voltage is doubled while the resistance is quadrupled. What would be the expected change for the current across this circuit?

### A

current decreases by 50%

### B

current stays the same

### C

current increases by 50%

### D

current increases by 100%

Tags: Circuits |

71

### Q:

Two resistors in series (of resistance 4 ohm and 12 ohm) are placed in parallel with a resistor of resistance 8 ohm. What is the approximate resultant resistance of the circuit?

4 ohm

5 ohm

7 ohm

8 ohm

Tags: Circuits |

72

### Q:

Four wires in a circuit for Christmas lights meet at a central point X. The current in three of the wires is measured and it is found that each wire has a current of 3 A directed towards point X. Which of the following is the current and direction of current in the fourth wire?

0 A

### B

3 A directed towards point X

### C

3 A directed away from point X

### D

9 A directed away from point X

Tags: Circuits |

73

### Q:

A 300V battery is connected with three resistors in parallel. These resistors have resistance 50 ohm, 150 ohm and 200 ohm. What is the voltage across the 200 ohm resistor?

75 V

150 V

200 V

300 V

Tags: Circuits |

74

### Q:

Approximately how much energy is stored on a capacitor of capacitance 25 F with a circuit voltage of 5 V?

125 J

250 J

310 J

360 J

Tags: Circuits |

75

### Q:

Three capacitors of capacitance 3X are placed in series. What is the resultant capacitance?

1/3X

1/X3

X

3X

Tags: Circuits |

76

### Q:

Which of the following is true for a dielectric material?

### A

When placed in an electric field, electric charge begins to flow through the material.

### B

They serve the same purpose as conductors within a circuit.

### C

They are important components of voltmeters in circuits.

### D

They may be used in the manufacture of capacitors.

Tags: Circuits |

77

### Q:

What voltage would be expected in a circuit with a total resistance of 15 ohms and a current of 15 amps?

1 V

30V

15V

225V

Tags: Circuits |

78

### Q:

Three capacitors of capacitance Y are placed in series and then this series of capacitors is placed in parallel to a capacitor of capacitance X. What is the resultant capacitance?

X + 3Y

X + Y/3

(X + Y)/3

3XY/(X + 3Y)

Tags: Circuits |

79

### Q:

Each plate of a capacitor is measured to have a charge of 5 mA and a resultant voltage of 10 mV. Which of the following is the capacitance of this system?

1 mF

1 F

0.5 mF

### D

0.5 F

Tags: Electrostatics | Circuits |

80

### Q:

What is the resultant capacitance if three capacitors of capacitance 4X are placed in series?

X/64

4X/3

16X/3

12X

Tags: Circuits |

81

### Q:

A resistor is constructed such that its cross-section is a square with length x. By what factor will resistivity change if this cross-sectional length is increased to 2x?

1/16

1/4

4

16

Tags: Circuits |

82

### Q:

Which of the following is the correct total resistance of X resistors placed in series, each with a resistance of Y?

X * Y

X / Y

Y / X

1 / (X * Y)

Tags: Circuits |

83

### Q:

Which of the following holds true for the energy stored in a charged capacitor?

### A

It is independent of the capacitance of the capacitor.

### B

It is independent of the charge stored in the capacitor.

### C

It is equivalent to the ratio of the charge stored on the capacitor and the voltage across the capacitor.

### D

It can be calculated as half of the product of charge and voltage of the capacitor.

Tags: Circuits |

84

### Q:

A farad may also be expressed as which of the following expressions?

joule per volt

### B

ampere per second

watt per ampere

coulomb per volt

Tags: Circuits |

85

### Q:

A household radio uses a household voltage of 110 volts to generate a current of 25 amps through its circuit. What is the resistance of the radio?

3.6 ohms

4.4 ohms

5.2 ohms

### D

6 ohms

Tags: Circuits |

Subscribe

Connect

Questions? We're here to help!