Final Exam Review 1.Electricity and Magnetism …...Final Exam Review 1.Electricity and Magnetism Name Free Response 1.Calculate the resistance of a 2000m length of nichrome wire with

Final Exam Review 1.Electricity and Magnetism NameFree Response

1. Calculate the resistance of a 2000m length ofnichrome wire with a cross-sectional area of 8.50 × 10–6 meter2 at 20°C. [Show all work, including theequation and substitution with units.]

2. Calculate the resistance of a 2000m length ofnichrome wire with a cross-sectional area of 8.50 × 10–6 meter2 at 20°C. [Show all work, including theequation and substitution with units.]

Base your answers to questions 3 through 6 on the diagram and information below and on yourknowledge of physics.

A 15-ohm resistor, 30-ohm resistor, and an ammeter are connected as shown with a 60-volt battery.

3. If another resistor were added in parallel to the original circuit, what effect would this have on thecurrent through resistor R1 ?

4. Calculate the rate at which the battery supplies energy to the circuit. [Show all work, including theequation and substitution with units.]

5. Determine the current measured by the ammeter

6. Calculate the equivalent resistance R1 and R2 . [Show all work, including the equation andsubstitution with units.]

7. A bolt of lightning transfers 28 coulombs of charge through an electric potential difference of 3.2 x 107 volts between a cloud and the ground in 1.5 x 10-3 second. Calculate the average electric currentbetween the cloud and the ground during this transfer of charge. [Show all work, including theequation and substitution with units.]

8. An operating television set draws 0.71 ampere of current when connected to a 120-volt outlet.Calculate the time it takes the television to consume 3.0 x 105 joules of electronic energy. [Show allwork, including the equation and substitution with units.]

1.Electricity and Magnetism

9. On the diagram sketch at least four magnetic field lines of force around a bar magnet. [Include arrowsto show the direction of each field line.]

Base your answers to questions 10 through 13 on the information below and on your knowledge ofphysics.

The Great Nebula in the constellation Orion consists primarily of excited hydrogen gas. Theelectrons in the atoms of excited hydrogen have been raised to higher energy levels. When theseatoms release energy, a frequent electron transition is from the excited n = 3 energy level to the n = 2energy level, which gives the nebula one of its characteristic colors.

10. Identify the color of light associated with this photon.

11. Calculate the frequency of the emitted photon. [Show all work, including the equation andsubstitution with units.]

12. Determine the energy of this emitted photon in joules.

13. Determine the energy, in electronvolts, of an emitted photon when an electron transition from n = 3to n = 2 occurs.


A 12-volt battery causes 0.60 ampere to flow through a circuit that contains a lamp and a resistorconnected in parallel. The lamp is operating at 6.0 watts.

14. Calculate the resistance of the resistor. [Show all work, including the equation and substitution withunits.]

15. Determine the current in the resistor.

16. Calculate the current through the lamp. [Show all work, including the equation and substitution withunits.]

17. Using the circuit symbols shown on the Reference Table, draw a diagram of the circuit.


A student constructed a series circuit consisting of a 12.0-volt battery, a 10.0-ohm lamp, and aresistor. The circuit does not contain a voltmeter or an ammeter. When the circuit is operating, thetotal current through the circuit is 0.50 ampere.

18. Calculate the power consumed by the lamp. [Show all work, including the equation and substitutionwith the units.]

19. Determine the resistance of the resistor.


20. Determine the equivalent resistance of the circuit.

21. In the space, draw a diagram of the series circuit constructed to operate the lamp, using symbols fromthe Reference Tables for Physical Setting/Physics.

Base your answers to questions 22 and 23 on the information below.

A 20.-ohm resistor, R1, and a resistor of unknown resistance, R2, are connected in parallel to a30.-volt source, as shown in the circuit diagram below. An ammeter in the circuit reads 2.0amperes.

22. Calculate the resistance of resistor R 2. [Show all work, including the equation and substitution withunits.]


24. The diagram below shows the north pole of one bar magnet located near the south pole of another barmagnet.

Draw three magnetic field lines in the region between the magnets.

25. A 25.0-meter length of platinum wire with a cross-sectional area of has aresistance of 0.757 ohm at 20°C. Calculate the resistivity of the wire. [Show all work, includingthe equation and substitution with units.]


Base your answers to questions 26 and 27 on the information below.

A 15-ohm resistor and a 20.-ohm resistor are connected in parallel with a 9.0-volt battery. Asingle ammeter is connected to measure the total current of the circuit.

26. Calculate the equivalent resistance of the circuit. [Show all work, including the equation andsubstitution with units.]

27. In the space below, draw a diagram of this circuit using symbols from the Reference Tables forPhysical Setting/Physics. [Assume the availability of any number of wires of negligible resistance.]

Base your answers to questions 28 and 29 on the information and diagram below.

A circuit contains a 12.0-volt battery, an ammeter, a variable resistor, and connecting wires ofnegligible resistance, as shown below.

The variable resistor is a nichrome wire, maintained at 20.°C. The length of the nichrome wire may bevaried from 10.0 centimeters to 90.0 centimeters. The ammeter reads 2.00 amperes when the length ofthe wire is 10.0 centimeters.

28. Calculate the cross-sectional area of the nichrome wire. [Show all work, including the equation andsubstitution with units.]

29. Determine the resistance of the 10.0-centimeter length of nichrome wire.

_______________________

30. The heating element in an automobile window has aresistance of 1.2 ohms when operated at 12 volts.Calculate the power dissipated in the heatingelement. [Show all work, including the equation andsubstitution with units.]

31. A simple circuit consists of a 100.-ohm resistorconnected to a battery. A 25-ohm resistor is to beconnected in the circuit. Determine the smallest equivalent resistance possible when both resistorsare connected to the battery.

_______________________


Base your answers to questions 32 and 33 on theinformation below.

A 3.50-meter length of wire with a crosssectionalarea of 3.14 x 10-6 meter2 is at 20° Celsius. Thecurrent in the wire is 24.0 amperes when connectedto a 1.50-volt source of potential difference.

32. Calculate the resistivity of the wire. [Show all work,including the equation and substitution with units.]

33. Determine the resistance of the wire.

34. A 6-ohm resistor and a 4-ohm resistor are connectedin series with a 6-volt battery in an operating electriccircuit. A voltmeter is connected to measure thepotential difference across the 6-ohm resistor.In the space below, draw a diagram of this circuitincluding the battery, resistors, and voltmeter usingsymbols from the Reference Tables for Physicalsettings/Physics. Label each resistor with its value.[Assume the availability of any number of wires ofnegligible resistance.]

35. Calculate the resistance of a 900.-watt toasteroperating at 120 volts. [Show all work, including theequation and substitution with units.]

36. In the space below, draw a diagram of an operatingcircuit that includes:a battery as a source of potential differencetwo resistors in parallel with each otheran ammeter that reads the total current in the circuit

37. On the diagram below, sketch at least four electricfield lines with arrowheads that represent the electricfield around a negatively charged conducting sphere.

38. Two oppositely charged parallel metal plates, 1.00centimeter apart, exert a force with a magnitude of3.60 × 10-15 newton on an electron placed betweenthe plates. Calculate the magnitude of the electricfield strength between the plates. [Show all work,including the equation and substitution with units.]


Base your answers to questions 39 through 41 on the information below.

A 5.0-ohm resistor, a 10.0-ohm resistor, and a 15.0-ohm resistor are connected inparallel with a battery. The current through the 5.0-ohm resistor is 2.4 amperes.

39. A 20.0-ohm resistor is added to the circuit in parallel with the other resistors. Describe the effect theaddition of this resistor has on the amount of electrical energy expended in the 5.0-ohm resistor in 2.0minutes.

40. Calculate the amount of electrical energy expended in the 5.0-ohm resistor in 2.0 minutes. [Show allwork, including the equation and substitution with units.]

41. Using the circuit symbols found in the Reference Tables for Physical Setting/Physics, draw a diagramof this electric circuit.


The centers of two small charged particles are separated by a distance of 1.2 × 10–4 meter. The chargeson the particles are +8.0 × 10–19 coulomb and +4.8 × 10–19 coulomb, respectively.

42. On the diagram below, draw at least four electric field lines in the region between the two positivelycharged particles.

43. On the axes below, sketch a graph showing the relationship between the magnitude of theelectrostatic force between the two charged particles and the distance between the centers of theparticles.

44. Calculate the magnitude of the electrostatic force between these two particles. [Show all work,including the equation and substitution with units.]

45. A length of copper wire and a 1.00-meter-long silverwire have the same cross-sectional area andresistance at 20°C. Calculate the length of the copperwire. [Show all work, including the equation andsubstitution with units.]


46. The diagram below represents two electrons, e1 ande2, located between two oppositely charged parallelplates

Compare the magnitude of the force exerted by theelectric field on e1 to the magnitude of the forceexerted by the electric field on e2.

Base your answers to questions 47 through 49 on theinformation and diagram below.

A 15-ohm resistor R1, and a 30-ohm resistor, R2, are to be connected in parallel between points A and B in a circuit containing a 90-volt battery.

47. Calculate the current in resistor R 1. [Show all work,including the equation and substitution with units.]

48. Determine the potential difference across resistor R 1.

49. "Complete the diagram above, to show the tworesistors connected in parallel between points A and B."

Base your answers to questions 50 and 51 on theinformation and diagram below.

A 10.0-meter length of copper wire is at 20ºC.The radius of the wire is 1.0 × 10-3 meter.

50. Calculate the resistance of the wire. [Show all work,including the equation and substitution with units.]

51. Determine the cross-sectional area of the wire.

52. Two small identical metal spheres, A and B, oninsulated stands, are each given a charge of +2.0 ×10–6 coulomb. The distance between the spheres is2.0 × 10–1 meter. Calculate the magnitude of theelectrostatic force that the charge on sphere A exertson the charge on sphere B. [Show all work,including the equation and substitution with units.]

53. An electric circuit contains a source of potentialdifference and 5-ohm resistors that combine to givethe circuit an equivalent resistance of 15 ohms. Drawa diagram of this circuit using circuit symbols givenin the Reference Tables for Physical Setting/Physics.[Assume the availability of any number of 5-ohmresistors and wires of negligible resistance.]


A copper wire at 20°C has a length of 10.0meters and a cross-sectional area of 1.00 × 10–3 meter2. The wire is stretched, becomes longerand thinner, and returns to 20°C.

54. What effect does this stretching have on the wire’sresistivity?

55. What effect does this stretching have on the wire’sresistance?


Base your answers to questions 56 through 58 on theinformation below.

A 3.0-ohm resistor, an unknown resistor, R, and two ammeters, A1 and A2, are connected asshown with a 12-volt source. Ammeter A2 reads acurrent of 5.0 amperes.

56. Calculate the resistance of the unknown resistor, R. [Show all work, including the equation andsubstitution with units.]

57. Calculate the current measured by ammeter A1.[Show all work, including the equation andsubstitution with units.]


Base your answers to questions 59 and 60 on thefollowing information.

The magnitude of the electric field strengthbetween two oppositely charged parallel metalplates is 2.0 × 103 newtons per coulomb. Point P is located midway between the plates.

59. An electron is located at point P between the plates.Calculate the magnitude of the force exerted on theelectron by the electric field. [Show all work,including the equation and substitution with units.]

60. On the diagram above, sketch at least five electricfield lines to represent the field between the twooppositely charged plates. [Draw an arrowhead oneach field line to show the proper direction.]


Base your answers to questions 61 through 63 on the information and diagram below.

A 50.-ohm resistor, an unknown resistor R, a 120-volt source, and an ammeter are connected in acomplete circuit. The ammeter reads 0.50 ampere.

61. Calculate the power dissipated by the 50.-ohm resistor. [Show all work, including the equation andsubstitution with units.]

62. Determine the resistance of resistor R.

___________

63. Calculate the equivalent resistance of the circuit. [Show all work, including the equation andsubstitution with units.]

64. A generator produces a 115-volt potential differenceand a maximum of 20.0 amperes of current.Calculate the total electrical energy the generatorproduces operating at maximum capacity for 60.seconds. [Show all work, including the equation andsubstitution with units.]

65. Calculate the resistance of a 1.00-kilometer length ofnichrome wire with a cross-sectional area of 3.50 × 10–6 meter2 at 20°C. [Show all work,including the equation and substitution with units.]

66. The diagram below shows two resistors, R1and R2,connected in parallel in a circuit having a 120-voltpower source. Resistor R1develops 150 watts andresistor R2develops an unknown power. Ammeter A in the circuit reads 0.50 ampere.

Calculate the amount of charge passing throughresistor R2 in 60 seconds. [Show all work, includingthe equation and substitution with units.]


Base your answers to questions 67 through 69 on theinformation below.

An 18-ohm resistor and a -ohm resistor areconnected in parallel with a -volt battery. Asingle ammeter is placed in the circuit to read itstotal current.

67. Calculate the total power dissipated in the circuit.[Show all work, including the equation andsubstitution with units.]

68. Calculate the equivalent resistance of the circuit.[Show all work, including the equation andsubstitution with units.]

69. Draw a diagram of this circuit using symbols fromthe Reference Tables for Physical Setting/Physics.[Assume the availability of any number of wires ofnegligible resistance.]

70. On the diagram of the bar magnet, draw a minimumof four field lines to show the magnitude anddirection of the magnetic field in the regionsurrounding the bar magnet.

71. An electron is accelerated through a potentialdifference of volts in the cathode ray tube ofa computer monitor. Calculate the work, in joules,done on the electron. [Show all work, including theequation and substitution with units.]


Base your answers to questions 72 through 75 on the information, circuit diagram, and data tablebelow.

In a physics lab, a student used the circuit shown to measure the current through and thepotential drop across a resistor of unknown resistance, R. The instructor told the student to use theswitch to operate the circuit only long enough to take each reading. The student’s measurementsare recorded in the data table.

72. Calculate the slope of the line or curve of best fit. [Show all work, including the equation andsubstitution with units.]

73. Draw the line or curve of best fit.

74. Plot the data points for potential drop versus current.

75. Mark an appropriate scale on the axis labeled “Potential Drop (V).”


Base your answers to questions 76 through 79 on the information in the data table and the gridprovided by following the directions below.

An experiment was performed using various lengths of a conductor of uniform crosssectionalarea. The resistance of each length was measured and the data recorded in the table below.

76. Calculate the slope of the best-fit line.

77. Draw the best-fit line.

78. Plot the data points for resistance versus length.

79. Mark an appropriate scale on the axis labeled “Length (m).”


Base your answers to questions 80 through 82 on theinformation and graph below.

A student conducted an experiment todetermine the resistance of a lightbulb. As sheapplied various potential differences to the bulb,she recorded the voltages and correspondingcurrents and constructed the graph below.

80. While performing the experiment the student noticedthat the lightbulb began to glow and became brighteras she increased the voltage. Of the factors affectingresistance, which factor caused the greatest changein the resistance of the bulb during her experiment?

A) decreasedB) increasedC) changed, but there is not enough information to

know which way

81. According to the graph, as the potential differenceincreased, the resistance of the lightbulb

82. The student concluded that the resistance of thelightbulb was not constant. What evidence from thegraph supports the student’s conclusion?


A lightweight sphere hangs by an insulatingthread. A student wishes to determine if thesphere is neutral or electrostatically charged. Shehas a negatively charged hard rubber rod and apositively charged glass rod. She does not touchthe sphere with the rods, but runs tests bybringing them near the sphere one at a time.

83. Describe the test result that would prove that thesphere is positively charged.

84. Describe the test result that would prove that thesphere is neutral.

85. A long copper wire was connected to a voltagesource. The voltage was varied and the currentthrough the wire measured, while temperature washeld constant. The collected data are represented bythe graph below.

Using the graph, determine the resistance of thecopper wire.

86. Base your answer to the following question on theinformation below.

A proton starts from rest and gains joule of kinetic energy as it accelerates betweenpoints A and B in an electric field.

Calculate the potential difference between points A and B in the electric field. [Show all work, includingthe equation and substitution with units.]


Base your answers to questions 87 through 91 on theinformation and data table below.

Three lamps were connected in a circuit with abattery of constant potential. The current,potential difference, and resistance for each lampare listed in the data table below. [There isnegligible resistance in the wires and the battery.]

87. If lamp 3 is removed from the circuit, what would bethe value of the current in lamp 2 after lamp 3 isremoved?

88. If lamp 3 is removed from the circuit, what would bethe value of the potential difference across lamp 1after lamp 3 is removed?

89. Calculate the equivalent resistance of the circuit.

90. What is the potential difference supplied by thebattery?

91. Using the circuit symbols found in the ReferenceTables for Physical Setting/Physics, draw a circuitshowing how the lamps and battery are connected.

92. A light bulb attached to a 120.-volt source ofpotential difference draws a current of 1.25 amperesfor 35.0 seconds. Calculate how much electricalenergy is used by the bulb.[Show all work, includingthe equation and substitution with units.]

93. What is the magnitude of the charge, in coulombs, ofa lithium nucleus containing three protons and fourneutrons?

94. The diagram below represents a wire conductor, RS, positioned perpendicular to a uniform magnetic fielddirected into the page.

Describe the direction in which the wire could bemoved to produce the maximum potential differenceacross its ends, R and S.


A 1.00-meter length of nichrome wire with across-sectional area of 7.85 × 10-7 meter2 isconnected to a 1.50-volt battery.

95. Determine the current in the wire.

96. Calculate the resistance of the wire.

97. Base your answer to the following question on thecircuit diagram below, which shows two resistorsconnected to a 24-volt source of potential difference.

On the diagram above, use the appropriate circuitsymbol to indicate a correct placement of a voltmeterto determine the potential difference across thecircuit.


98. Your schools physics laboratory has the followingequipment available for conducting experiments:

Explain how you would find the resistance of anunknown resistor in the laboratory. Your explanationmust include:

a Measurements requiredb Equipment neededc Complete circuit diagramd Any equation(s) needed to calculate the resistance

Base your answers to questions 99 through 102 on the information and data table below.

A variable resistor was connected to a battery. As the resistance was adjusted, the current andpower in the circuit were determined. The data are recorded in the table below.

99. What is the physical significance of the slope of the graph?

100. Calculate the slope of the graph. [Show all calculations, including the equation and substitution withunits.]

101. Using your graph, determine the power delivered to the circuit at a current of 3.5 amperes.

102. Using the information in the data table, construct a line graph on the grid provided above, followingthe directions below.

a Plot the data points for power versus current.b Draw the best-fit line.


Base your answers to questions 103 and 104 on thefollowing information:

A toaster having a power rating of watts isoperated at volts.

103. The toaster is connected in a circuit protected by a15-ampere fuse. (The fuse will shut down thecircuit if it carries more than 15 amperes.) Is itpossible to simultaneously operate the toaster and amicrowave oven that requires a current of 10.0amperes on this circuit? Justify your answermathematically.

104. Calculate the resistance of the toaster. [Show allwork, including the equation and substitution withunits.]


An electric circuit contains two -ohmresistors connected in parallel with a battery. Thecircuit also contains a voltmeter that reads thepotential difference across one of the resistors.

105. Calculate the total resistance of the circuit. [Showall work, including the equation and substitutionwith units.]

106. Draw a diagram of this circuit, using the symbolsfrom the Reference Tables for PhysicalSetting/Physics. [Assume availability of anynumber of wires of negligible resistance.]

107. The diagram below shows two compasses locatednear the ends of a bar magnet. The north pole ofcompass X points toward end A of the magnet.

On the diagram above, draw the correct orientationof the needle of compass Y and label its polarity.


Base your answers to questions 108 through 110 on the passage below and on your knowledge ofphysics.

Forces of Nature

Our understanding of the fundamental forces has evolved along with our growing knowledgeof the particles of matter. Many everyday phenomena seemed to be governed by a long list ofunique forces. Observations identified the gravitational, electric, and magnetic forces as distinct. Alarge step toward simplification came in the mid-19th century with Maxwell's unification of theelectric and magnetic forces into a single electromagnetic force. Fifty years later came therecognition that the electromagnetic force also governed atoms. By the late 1800s, all commonlyobserved phenomena could be understood with only the electromagnetic and gravitational forces.

Particle Physics–Perspectives and Opportunities (adapted)

(A hydrogen atom, consisting of an electron in orbit about a proton, has an approximate radius of 10–10 meter.)

108. In the above passage there is an apparent contradiction. The author stated that "the electromagneticforce also governed atoms." He concluded with "all commonly observed phenomena could beunderstood with only the electromagnetic and gravitational forces."

Use your responses from the previous questions to explain why the gravitational interaction isnegligible for the hydrogen atom.

109. Determine the order of magnitude of the gravitational force between the electron and the proton.

110. Determine the order of magnitude of the electrostatic force between the electron and the proton.


You are given a -volt battery, ammeter , voltmeter , resistor , and resistor . Resistor R2 has a value of ohms.

111. If the total current in the circuit is amperes, determine the resistance of resistor . [Show allcalculations, including the equation and substitution with units.]

112. If the total current in the circuit is 6.0 amperes, determine the equivalent resistance of the circuit.[Show all calculations, including the equation and substitution with units.]

113. Using appropriate symbols from the Reference Tables for Physical Setting/Physics, draw and label acomplete circuit showing:

• resistors R 1 and R 2 connected in parallel with the battery• the ammeter connected to measure the current through resistor R 1, only• the voltmeter connected to measure the potential drop across resistor R 1


114. Four small metal spheres , , , and on insulating stands act on each other by means ofelectrostatic forces.

It was known that sphere is negatively charged. The following observations were made:

• Sphere attracts all the other spheres.• Spheres and repel each other.• Sphere attracts all the other spheres.

Determine the charge on each sphere and complete the table above noting for each sphere if it ispositive , negative , or neutral .

115. The circuit shown below contains two resistors, R 1 and R 2 .

a What is the resistance of resistor R 2 ?[Show all calculations, including the equation and substitution with units.]

b What is the power of this circuit?[Show all calculations, including the equation and substitution with units.]


Base your answers to questions 116 through 118 on the information and diagram below.

Two small charged spheres, A and B, are separated by a distance of 0.50 meter. Thecharge on sphere A is +2.4 ×10-6 coulomb and the charge on sphere B is –2.4 ×10-6 coulomb.

116. Using the axes above, sketch the general shape of the graph that shows the relationship between themagnitude of the electrostatic force between the two charged spheres and the distance separatingthem. The charge on each sphere remains constant as the distance separating them is varied.

117. Calculate the magnitude of the electrostatic force that sphere A exerts on sphere B. [Show allcalculations, including the equation and substitution with units.]

118. On the diagram, sketch three electric field lines to represent the electric field in the region betweensphere A and sphere B. [Draw an arrowhead on each field line to show the proper direction.]


A 5.0-ohm resistor, a 15.0-ohm resistor, and an unknown resistor, R, are connected asshown with a 15-volt source. The ammeter reads a current of 0.50 ampere.

119. Determine the total electrical energy used in the circuit in 600. seconds. [Show all calculations,including the equation and substitution with units.]


120. a Determine the reading of the voltmeter connected across the 5.0-ohm resistor. [Show allcalculations, including the equation and substitution with units.]

b Determine the total resistance of the circuit. [Show all calculations, including the equation andsubstitution with units.]

c Determine the resistance of the unknown resiter, R.

121. Base your answers to parts a and b on the information below.

Two resistors are connected in parallel to a 12-volt battery. One resistor, R1, has a value of 18 ohms.The other resistor, R2, has a value of 9 ohms. The total current in the circuit is 2 amperes. A studentwishes to measure the current through R, and the potential difference across R2.

a Using the symbols from your Reference Table, draw and label a circuit diagram that will enablethe student to make the desired measurements.

b Calculate the value of the current in resistor R1. (Show all calculations, including equations andsubstitutions with units.)


122. Base your answers to parts a through c on the information and data table below.

A resistor was held at constant temperature in an operating electric circuit. A student measured thecurrent through the resistor and the potential difference across it. The measurements are shown inthe data table below.

a Using the information in the data table, construct a graph on the grid provided following thedirections below.(1) Mark an appropriate scale on the axis labeled "Current (A)"(2)Plot the data points for potential difference versus current.(3)Draw the best-fit line.

b Using your graph, find the slope of the best-fit line. [Show all calculations, including the equationand substitution with units.]

c What physical quantity does the slope of the graph represent?



Two parallel plates separated by a distance of 2.0 x 10- 2 meter are charged to a potentialdifference of 1.0 x 102 volts. Points A, B, and C are located in the region between theplates.

123. Calculate the magnitude of the electric field strength between the plates. [Show all calculations,including the equation and substitutions with units.]

124. On the diagram, sketch the electric field lines between the oppositely charged parallel plates throughpoints A, B, and C. [Draw lines with arrowheads in the proper direction.]


A 5.0-ohm resistor, a 20.0-ohm resistor, and a 24-volt source of potential difference areconnected in parallel. A single ammeter is placed in the circuit to read the total current.

125. Determine the total circuit current. [Show all calculations, including the equation and substitutionwith units.]

126. Determine the total circuit resistance. [Show all calculations, including the equation and substitutionwith units.]

127. Draw a diagram of this circuit, using the symbols and labels from your Reference Table.[Assume availability of any number of wires of negligible resistance.]


A scientist set up an experiment to collect data about lightning. In one lightning flash, a charge of 25coulombs was transferred from the base of a cloud to the ground. The scientist measured a potentialdifference of 1.8 × 106 volts between the cloud and the ground and an average current of 2.0 × 101 amperes.

128. The scientist was several kilometers from the lightning flash. Using one or more completesentences, explain why the scientist saw the lightning flash several seconds before he heard thesound of the thunderclap from that flash.


129. Determine the amount of energy, in joules, involved in the transfer of the electrons from the cloud tothe ground.[Show all calculations, including the equation and substitution with units.]

130. Determine the time interval over which this flash occurred.[Show all calculations, including the equation and substitution with units.]

Base your answers to questions 131 through 134 on the information and circuit diagram below and onyour knowledge of physics.

Three lamps are connected in parallel to a 120.-volt source of potential difference, as representedbelow.

131. The circuit is disassembled. The same three lamps are then connected in series with each other andthe source. Compare the equivalent resistance of this series circuit to the equivalent resistance of theparallel circuit.

132. Describe what change, if any, would occur in the equivalent resistance of the circuit if the 60.-wattlamp were to burn out.

133. Describe what change, if any, would occur in the power dissipated by the 100.-watt lamp if the60.-watt lamp were to burn out

134. Calculate the resistance of the 40.-watt lamp. [Show all work, including the equation andsubstitution with units.]


Base your answers to questions 135 through 138 on the information and diagram below and on yourknowledge of physics.

Two conducting parallel plates meter apart are charged with a 12-volt potentialdifference. An electron is located midway between the plates. The magnitude of the electrostaticforce on the electron is newton.

135. Describe what happens to the magnitude of the net electrostatic force on the electron as the electronis moved toward the positive plate.

136. Calculate the magnitude of the electric field strength between the plates, in newtons per coulomb.[Show all work, including the equation and substitution with units.]

137. Identify the direction of the electrostatic force that the electric field exerts on the electron.

138. On the diagram, draw at least three field lines to represent the direction of the electric field in thespace between the charged plates.

Answer Keyjjd

1.

2.

3. No effect or Thecurrent wouldremain the same.

4.

5. 6.0 A6.

7.

8.

9.

10. Red or for an answerthat is consistentwith the student'sresponse to question84.

11. Equation andsubstitution withunits or for ananswer, with units,that is consistentwith the student'sresponse to question82.

12. 3.02 x 10-19 J or foran answer that is theproduct of thestudent's response toquestion 81 and 1.60x 10-19 J/eV.

13. 1.89 eV.14. Equation and

substitution withunits or for ananswer that isconsistent with thestudent's response toquestion 78.

15. 0.10 A or for ananswer that is thedifference betweenthe student'sresponse to question77 and 0.60 A or foran answer that isconsistent with thestudent's response toquestion 75.

16. Equation andsubstitution withunits.

17. Correct circuitdiagram.

18. P = 2.5 W19.20.21.

22.

23. 15 24.

25. or

26. Req = 8.6 27.

28.

29. 6.00 30.

31. 20.

32.

33. 6.25 × 10–2

34.

35.

36.

37.

38.

39. The energyexpended in the5.0-ohm resistorremains the same.

40.

Answer Keyjjd

41.

42.

43.

44.

45.

46. the magnitude of theforce on eachelectron is the same

47. 6.0 A48. 90 V49.

""

50. 5.5 × 10-2

51. 3.1 × 10–6 m2

52. 9.0 × 10–1 N53.

54. the resistivityremains the same

55. resistance increases56. R= V / I

R= 12 V / 1.0 AR= 12 ohms

57. R= V/II= V/RI = 12 V / 3.0 ohmsI= 4.0 A

58. 2.4 ohms59. E= Fe/q

Fe=Eq

Fe= (2.0 × 10 N/C)(1.6 × 10 C)Fe= 3.2 × 10 N

60.

61. P = I2RP = (0.50 A)2 (50. )P = 12 W or 12.5 W

62. 190 63.

64. W = VItW = (115 V) (20.0 A)(60. s)W = 1.4 × 105 J or 138 000 J

65.

66. I = q

t

q = It

q = (0.50 A)(60. s)q = 30. C

67.

68.

69.

70.

71.

72.

73.

74. Students should plotall points accurately(±0.3 grid space).

75. Students shouldmake an appropriatescale on the axislabeled “PotentialDrop (V).”

76. 0.32 /m77.

78.

79. Student shouldcreate a scale that islinear and hasappropriatedivisions.

80. Examples: — As thevoltage increased,the temperatureincreased, causing ahigher resistance. — The bulb gothotter. — the temperatureof the bulb— resistivity

81. B82. Examples: — The

slope changes. —The line (or graph)curves. — The graphis not a straight line.

83. Allow credit forindicating that thesphere is repelled bythe positive rod(only).

Answer Keyjjd

84. Allow credit forindicating that thesphere is attracted toboth rods.

85. Allow credit for 25.0(±1.7) .

86.

87. 0.11 A88. 40.1 V89. Req = 48 or 47.790. 40.1 V91.

92. W = VItW = (120. V)(1.25A)(35.0 s)W = 5250 J

93. 4.80 × 10–19 C or 4.8 × 10–19 C.

94. Examples:horizontally; left toright; right to left;perpendicular toboth the length ofthe wire and themagnetic field;toward the xs

95. 0.785 A96. R = 1.9197.

98.

99. examples:– voltage – potentialdifference

100.

101. P = 10.5 W102.

103. I = = =8.75AI total = 8.75A +10.0A =18.8AAnswer = No

104.

105.

106.

107.

108. Credit for explainingwhy gravitationalinteraction isnegligible for thehydrogen atom byusing responses tothe above twoquestions• The electrostaticforce is 1039 strongerthan thegravitational force• The Gravitationalforce is smaller thanthe electromagneticinteraction

109. Credit for 10-47

110. Credit for 10-8

111.

112. Credit for 2.0 V or 2V

113.

114.

115. a) 6 Ohms b) 8 W116. sketch117. F = 2.1 × 10-1 N

118.

119. 4500 J120. a) 2.5 Volts

b) 30 Ohms c) 10 Ohms

121. A) DrawingB) I = 0.67 A

122. A) graphB) slope = 250 ohmsC) Resistance

123. E = 5 × 103 V/m124. Sketch125. I = 6 A or 6 V/Ohms126. R = 4 ohms127. drawing128. Light travels much

faster than sound.The speed of light is3.0 × 108 m/s andthe speed of sound isonly 3.3 × 102 m/s

129. W = 4.5 × 107 J or W = 45 × 106 V•C

130. t = 1.25s or t =1.25C/A

131. indicating that theequivalent resistanceof the series circuitwould be greaterthan the equivalentresistance of theparallel circuit.

132. the equivalentresistance wouldincrease.

133. there would be nochange in the powerdissipated.

Answer Keyjjd

134.

135. — The force willremain constant. —The force doesn'tchange.

136.

137. — toward thepositive plate —toward the top of thepage — opposite thedirection of the field

138.

Documents

Final Exam Review 1.Electricity and Magnetism …...Final Exam Review 1.Electricity and Magnetism Name Free Response 1.Calculate the resistance of a 2000m length of nichrome wire with