Download Physics Final Exam Study Guide 3

Physics Final Exam Study Guide 3
Multiple Choice
Identify the choice that best completes the statement or answers the question.
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1. In the top of a barometer there is a space that is filled with _____.
a. helium
b. dense mercury vapor
c. water vapor
d. air
e. none of the above
2. One barometer tube has twice the cross-sectional area of another. Mercury in the smaller tube will rise _____.
a. the same height as in the larger tube
b. four times as high as mercury in the larger tube
c. twice as high as mercury in the larger tube
d. more than four times as high as in the larger tube
e. none of the above
3. Air pressure in a tire depends on _____.
a. the density of air inside the tire
b. the number of molecular collisions each second
c. the temperature of the air inside the tire
d. the impact of the molecular collisions on the tire
e. all of the above
4. Boyle's law relates _____.
a. pressure and number of molecules
b. pressure and temperature
c. pressure and volume
d. temperature and volume
e. none of the above
5. If you squeeze a balloon to one half its original size, the pressure inside _____.
a. decreases by a factor of 2
b. decreases by a factor of 4
c. stays the same
d. increases by a factor of 2
e. increases by a factor of 4
6. The air in your classroom has _____.
a. mass
b. energy
c. weight
d. temperature
e. all of the above
7. As a woman holding her breath swims deeper and deeper beneath the water's surface, her density _____.
a. decreases
b. remains the same
c. increases
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8. Consider an air-filled balloon, weighted with a stone, that just barely floats in water. When the balloon is
pushed beneath the surface, say about a meter deep, and then released, it will _____.
a. stay where it is
b. sink
c. float back to the surface
9. Which has the larger buoyant force, a balloon filled with helium or a balloon the same size filled with air?
a. The air balloon
b. The helium balloon
c. Neither — they both experience the same buoyant force.
10. Which has more weight, a balloon filled with helium or a balloon the same size filled with air?
a. The air balloon
b. The helium balloon
c. Neither — they both have the same weight.
11. A balloon is buoyed up with a force equal to the _____.
a. atmospheric pressure
b. density of surrounding air
c. weight of air it displaces
d. weight of the balloon and contents
e. all of the above
12. A bubble of air released from the bottom of a lake _____.
a. becomes larger as it rises
b. becomes smaller as it rises
c. rises to the top at constant volume
d. alternately expands and contracts as it rises
e. none of the above
13. Compared to the buoyant force of the atmosphere on a 1-kilogram helium-filled balloon, the buoyant force of
the atmosphere on a nearby 1-kilogram solid iron block is _____.
a. considerably less
b. the same
c. considerably more
14. When a river narrows, the water in the river flows _____.
a. slower
b. at the same rate
c. faster
15. On a windy day, atmospheric pressure _____.
a. increases
b. remains unchanged
c. decreases
16. Bernoulli's principle says that _____.
a. internal fluid pressure decreases as the fluid speed increases
b. as volume of a gas increases at constant temperature, the pressure decreases
c. an object in air is buoyed up by a force equal to the weight of air displaced
d. internal fluid pressure increases as the fluid speed increases
e. as volume of a gas increases at constant temperature, the pressure increases
____ 17. Bernoulli's principle really comes from _____.
a. conservation of momentum
b. conservation of energy
c. the definition of acceleration
d. buoyant force considerations
e. the definition of pressure
____ 18. If you blow across the top of a piece of paper, the paper will _____.
a. do nothing
b. lift
c. flatten
d. flap wildly
____ 19. The reason a shower curtain will pull to the inside of a bathtub during a shower is that _____.
a. there is more water inside the curtain
b. there is less air inside the curtain
c. there is more air inside the curtain
d. there is more pressure inside the curtain
e. there is less pressure inside the curtain
____ 20. Which temperature scale labels the freezing point of water at 0 degrees?
a. Celsius
b. Caloric
c. Kelvin
d. Fahrenheit
e. none of the above
____ 21. Heat is the _____.
a. average amount of energy per molecule contained in an object
b. total amount of energy contained in an object
c. energy transferred between objects because of a temperature difference
d. amount of energy all the molecules have
e. all of the above
____ 22. Internal energy is the _____.
a. average amount of energy contained in an object
b. amount of energy that is transferred from one object to another object
c. total amount of energy contained in an object
d. amount of kinetic energy all the molecules have
e. all of the above
____ 23. Specific heat capacity is related to the amount of internal energy _____.
a. transferred by one molecule
b. one molecule contains
c. a specific object has
d. transferred by one object
e. needed to change the temperature of one gram of a substance one degree
____ 24. The fact that desert sand is very hot in the day and very cold at night is evidence that sand has a _____.
a. low specific heat capacity
b. high specific heat capacity
____ 25. Which, at the same temperature, will cool more slowly on a hot day?
a. Dry beans
b. Watermelon
c. Potatoes
d. Bread
e. All will cool at the same or similar rates.
____ 26. If the specific heat capacity of water were higher than it is, lakes would be _____.
a. more likely to freeze
b. less likely to freeze
c. neither of the above
____ 27. Which of the following expands most when the temperature is lowered?
a. Helium
b. Iron
c. Wood
d. Water at 4 degrees C
e. None of the above expands when the temperature is lowered.
____ 28. The reason fish live from year to year in ponds that freeze over in the winter is that _____.
a. fish are cold-blooded and can stand being frozen and thawed
b. fish swim so fast they keep the water from freezing under the surface
c. water below the ice is 4 degrees above freezing
d. fish hibernate during the winter
e. none of the above
____ 29. One thousand calories of heat are added to 150 grams of water when its temperature is 33°C. The resulting
temperature of the water is
a. 7°C
b. 32°C
c. 40°C
d. 80°C
e. 100°C
____ 30. A change in temperature of 10°C is equal to a change of
a. –273 K
b. 10 K
c. 263 K
d. 273 K
e. 283 K
____ 31. Mix a liter of 70°C water with 2 liters of 40°C water and you'll have 3 liters of water at _____.
a. 28°C
b. 50°C
c. 55°C
d. 60°C
____ 32. Mix 3 liters of 20°C water with 4 liters of 30°C water and you'll have 7 liters of water at _____.
a. 24°C
b. 32°C
c. 26°C
d. 28°C
____ 33. When 4 grams of a substance loses 4 calories in cooling 1°C, its specific heat capacity using water as the unit
of measure, is _____.
a. 1
b. 6
c. 10
d. 20
e. none of the above
____ 34. Plastic foam is a good heat
a. conductor.
b. insulator.
c. emitter.
d. absorber.
e. radiator.
____ 35. Heat travels from the sun to Earth by
a. conduction.
b. radiation.
c. convection.
d. insulation.
e. vacuumization.
____ 36. If a volume of air is warmed, it expands. If a volume of air expands, it
a. neither warms nor cools.
b. warms.
c. cools.
____ 37. A good absorber of radiation is
a. a good reflector.
b. a poor emitter of radiation.
c. a good emitter of radiation.
d. none of the above
____ 38. A piece of paper wrapped around a thick metal bar will not ignite when touched with a lit match because
a. energy goes to the bar, preventing ignition temperature in the paper.
b. the bar keeps the paper relatively cool.
c. the bar is slow to heat up.
d. all of the above.
____ 39. Newton's law of cooling says that the rate of cooling depends on
a. the temperature difference between an object and its surroundings.
b. the volume of an object.
c. the mass of an object.
d. the specific heat capacity of an object.
e. all of the above
____ 40. The lower atmosphere is directly warmed
a. by the emission of terrestrial radiation.
b. by incoming solar radiation.
c. from the weight of the atmosphere.
d. by absorption of terrestrial radiation.
____ 41. Firewalkers who walk barefoot on red-hot wooden coals depend on
a. wood's poor conductivity.
b. pure chance.
c. mind over matter.
____ 42. At night, a sea breeze results when
a. warm air over the shore rises and cooler air from the ocean takes its place.
b. warm air over the ocean rises and cooler air from the shore takes its place.
c. cool air over the shore rises and warmer air from the ocean takes its place.
d. cool air over the ocean rises and warmer air from the shore takes its place.
____ 43. Two pots are filled with boiling water. The pots are exactly the same size, but one pot is white and the other is
black. Which pots cools faster?
a. The black pot.
b. The white pot.
c. Neither—they both cool at the same rate.
____ 44. Evaporation takes place when matter changes from a
a. solid to a liquid.
b. solid to a gas.
c. liquid to a gas.
d. gas to a liquid.
e. gas to a solid.
____ 45. To say that evaporation is a cooling process means that when evaporation occurs,
a. the remaining liquid cools.
b. the evaporating vapor cools.
c. both A and B.
d. none of the above
____ 46. Pigs roll in the mud
a. to thermally insulate themselves.
b. to keep their skin wet so evaporation can occur.
c. because the darker color of mud makes them warmer.
d. none of the above
____ 47. Condensation occurs when matter changes from a
a. gas to a liquid.
b. solid to a gas.
c. solid to a liquid.
d. liquid to a gas.
e. gas to a solid.
____ 48. On which day will the amount of water vapor in the air be greater, a summer day at 100% humidity or a
winter day at 100% humidity?
a. The summer day
b. The winter day
c. Neither—at 100% humidity they both hold the same amount of water.
____ 49. Clouds form when warm air
a. expands.
b. rises.
c. chills.
d. all of the above
e. none of the above
____ 50. A liquid boils when
a. air molecules form a bubble and rise.
b. it turns to vapor at the bottom of or in the liquid.
c. trapped air in the liquid is heated.
d. trapped air in the liquid rises to the surface.
e. all of the above
____ 51. The reason pressure cookers cook food faster is that they
a. boil water faster.
b. raise the boiling point of water.
c. raise the cooking temperature of the food.
d. both A and C
e. both B and C
____ 52. Freezing occurs when matter changes from a
a. solid to a gas.
b. solid to a liquid.
c. gas to a solid.
d. liquid to a gas.
e. liquid to a solid.
____ 53. Steam burns are more damaging than burns caused by boiling water because steam
a. is a vapor of water molecules.
b. has a higher temperature than boiling water.
c. has more energy per kilogram than boiling water.
d. occupies more space than water.
e. none of the above
____ 54. Which would burn the most?
a. 100 g of water at 100 degrees C
b. 100 g of steam at 100 degrees C
c. Both would be equally damaging.
____ 55. As atmospheric pressure increases, the boiling temperature of a liquid
a. is 100 degrees C.
b. decreases.
c. increases.
d. remains unchanged.
____ 56. An air sample contains 25% of the amount of water vapor it is capable of holding. The air's relative humidity
is
a. 25%.
b. 50%.
c. 75%.
d. 125%.
e. none of the above
____ 57. When snow forms in clouds, the surrounding air
a. cools.
b. neither warms nor cools.
c. warms.
____ 58. Food cooked in boiling water in the mountains cooks more slowly than cooked at sea level. If the temperature
under the pot is increased, the food will cook
a. slower.
b. at the same rate as before.
c. faster.
____ 59. Morning dew on the grass is a result of
a. evaporation of water.
b. air pressure on water vapor.
c. the open-structured form of water crystals.
d. slow-moving molecules condensing on the grass.
e. none of the above
____ 60. The molecules in a room-temperature glass of water jostle around at
a. a great variety of speeds.
b. much the same rates of speed.
c. no speed (they are not moving).
____ 61. Ice is put in a cooler to cool the food stored there. In order to speed up the cooling process, you should
a. drain ice water from the cooler periodically.
b. wrap the ice in newspaper.
c. light a small fire under one end, causing air currents to form.
d. crush the ice.
e. keep the ice and food well separated.
____ 62. The greater the difference in temperature between the input reservoir and output reservoir for a heat engine,
the
a. less the efficiency.
b. greater the efficiency.
c. neither—efficiency doesn't depend on temperature difference.
____ 63. Two identical blocks of iron, one at 10 degrees C and the other at 20 degrees C, are put in contact. Suppose
the cooler block cools to 5 degrees C and the warmer block warms to 25 degrees C. This would violate the
a. first law of thermodynamics.
b. second law of thermodynamics.
c. both of the above
d. none of the above
____ 64. As a system becomes more disordered, entropy
a. remains the same.
b. decreases.
c. increases.
____ 65. Systems that are left alone tend to move toward a state of
a. more entropy.
b. less entropy.
c. no entropy.
____ 66. In buildings that are electrically heated, turning the lights on
a. doesn't waste energy.
b. wastes energy.
c. does neither of the above.
____ 67. Cool a sample of air from zero on the Celsius scale to near zero on the absolute scale and the air loses
a. volume.
b. pressure.
c. both A and B
d. neither A nor B
____ 68. The ideal efficiency for a heat engine operating between temperatures of 2050 K and 310 K is
a. 15%.
b. 50%.
c. 25%.
d. 85%.
e. none of the above.
____ 69. Atomic nuclei of almost all elements consist of
a. only neutrons.
b. protons and electrons.
c. neutrons and electrons.
d. only protons.
e. protons and neutrons.
____ 70. Two like charges
a. neutralize each other.
b. repel each other.
c. must be neutrons.
d. attract each other.
e. have no effect on each other.
____ 71. The fundamental force underlying all chemical reactions is
a. electrical.
b. gravitational.
c. centripetal.
d. nuclear.
e. none of the above
____ 72. Electrical forces between charges are strongest when the charges are
a. far apart.
b. close together.
c. The electrical force is constant everywhere.
____ 73. A positive ion has
a. more electrons than protons.
b. more protons than electrons.
c. a +1 charge always.
d. one proton.
____ 74. To say that electric charge is conserved means that no case has ever been found where
a. the total amount of charge on an object has increased.
b. one object has more charge than another object.
c. the total charge on an object has changed.
d. net charge has been created or destroyed.
e. none of the above
____ 75. The common hydrogen atom consists of
a. one electron.
b. one proton and one electron.
c. one proton.
d. two protons, one neutron, and two electrons.
e. one neutron and one electron.
____ 76. In a good insulator, electrons are usually
a. not moving at all.
b. free to move around after an impurity has been added.
c. free to move around.
d. tightly bound in place.
e. semi-free to move around.
____ 77. Charge carriers in a metal are electrons rather than protons, because electrons are
a. relatively far from a nucleus.
b. loosely bound.
c. lighter.
d. all of the above
e. none of the above
____ 78. To be safe in the unlikely case of a lightning strike, it is best to be inside a building framed with
a. steel.
b. wood.
c. either A or B.
____ 79. A conductor differs from an insulator in that a conductor has
a. more protons than electrons.
b. faster-moving molecules.
c. more electrons than protons.
d. more electrons than an insulator.
e. none of the above
____ 80. Much electronic equipment contains transistors and diodes that are made from semiconductors.
Semiconductors
a. can be very good insulators.
b. can conduct electricity.
c. contain helpful impurities.
d. all of the above
e. none of the above
____ 81. An electroscope is charged positively, as shown by foil leaves that stand apart. As a negatively charged rod is
brought close to the electroscope, the leaves
a. spread farther apart.
b. do not move.
c. move closer together.
____ 82. Lightning bolts occur between
a. clouds and the ground.
b. clouds.
c. both A and B.
____ 83. To charge an object by induction, the process of grounding
a. may or may not occur.
b. always occurs.
____ 84. When a charged cloud passes overhead, the ground below is charged by
a. induction.
b. polarization.
c. deduction.
d. electrification.
____ 85. Electrical polarization occurs when
a. an electron is at a different location than a proton.
b. charge distribution in a neutral molecule separates.
c. the electron and the proton are on different sides of an atom.
d. an atom vibrates in a single direction.
e. none of the above
____ 86. The charge distribution in some molecules is permanently separated into positive and negative regions. Such
molecules are called
a. ionized molecules.
b. electric dipoles.
c. coulomb molecules.
d. induced molecules.
e. insulators.
____ 87. Two charged particles held close to each other are released. As the particles move, the velocity of each
increases. Therefore, the particles have
a. the same sign.
b. opposite signs.
c. charges that cannot be determined.
____ 88. A positive charge and a negative charge held near each other are released. As they move, the force on each
particle
a. increases.
b. stays the same.
c. decreases.
____ 89. Particle A has twice as much charge as particle B. Compared to the force on particle A, the force on particle B
is
a. half as much.
b. two times as much.
c. four times as much.
d. the same.
e. none of the above
____ 90. Two charges separated by a distance of 1 meter exert a 20-N force on each other. If the charges are pulled to a
2 meter separation distance, the force on each charge will be
a. 0 N.
b. 5 N.
c. 10 N.
d. 40 N.
e. 80 N.
____ 91. Two charges separated by a distance of 1 meter exert a 2-N force on each other. If the magnitude of each
charge is doubled, the force on each charge is
a. 2 N.
b. 4 N.
c. 8 N.
d. 16 N.
e. none of the above
____ 92. Every proton in the universe is surrounded by its own
a. gravitational field.
b. electric field.
c. both A and B
d. none of the above
____ 93. The direction of electric field lines shows the
a. direction of the force on a test positive charge.
b. size of the field.
c. strength of the field.
d. all of the above
____ 94. Electrical potential energy is the energy a charged object has because of its
a. momentum.
b. location.
c. mass.
d. motion.
e. volume.
____ 95. Suppose a hollow metal sphere has a large number of extra electrons on it. The extra electrons will be located
a. only on the outside surface of the sphere.
b. only on the inside surface of the sphere.
c. both on the inside and outside surfaces of the sphere.
____ 96. The electric field outside a Van de Graaff generator may be enormous, while inside the spherical dome, the
electric field is
a. even more enormous.
b. almost as enormous.
c. zero.
____ 97. The electric field around an isolated electron has a certain strength 1 cm from the electron. The electric field
strength 2 cm from the electron is
a. half as much.
b. the same.
c. twice as much.
d. four times as much.
e. none of the above
____ 98. Two parallel plates are oppositely charged. The left plate is negative and the right plate is positive. In which
direction does the electric field point?
a. to the left
b. to the right
____ 99. The electric field lines between two charges curve in space. The direction at a particular point on a curved line
is the direction of the
a. strongest field.
b. average straight line joining the charges.
c. resultant vector of the fields of the two charges at that point.
d. none of the above
____ 100. Electrical potential energy per charge is electric
a. force.
b. power.
c. potential.
d. work.
____ 101. The electric field inside an uncharged metal ball is zero. If the ball gains a negative charge, the electric field
inside the ball will be
a. greater than zero.
b. less than zero.
c. zero.
____ 102. If you use 20 J of work to push a 2-C charge into an electric field, its voltage with respect to its starting
position is
a. 10 V.
b. less than 10 V.
c. more then 10 V.
____ 103. The electrical force on a 2-C charge is 20 N. What is the value of the electric field at the location of the
charge?
a. 2 N/C
b. 10 N/C
c. 20 N/C
d. 40 N/C
e. 80 N/C
____ 104. An electron is pushed into an electric field where it acquires a 7.0-V electric potential. If two electrons are
pushed the same distance into the same electric field, the electric potential of the two electrons is
a. 1.8 V.
b. 3.5 V.
c. 7.0 V.
d. 14.0 V.
e. 28.0 V.
____ 105. In solid conductors, electric current is the flow of
a. positive and negative charges.
b. electrons.
c. negative ions.
d. protons.
e. none of the above
____ 106. Electrons move in an electric circuit
a. by being bumped by other electrons.
b. by interacting with an established electric field.
c. by colliding with molecules.
d. because the wires are so thin.
e. none of the above
____ 107. An ampere is a
a. unit of resistance.
b. unit of current.
c. type of charge.
d. voltage.
e. current.
____ 108. Electrical resistance in a wire depends on the wire's
a. thickness.
b. conductivity.
c. length.
d. all of the above
e. none of the above
____ 109. For most conductors, as their temperature increases, their resistance
a. decreases.
b. increases.
c. stays the same.
____ 110. Electrical resistance is measured in
a. volts.
b. joules.
c. watts.
d. amperes.
e. none of the above
____ 111. The frequency of AC current in North America is
a. 120 V.
b. 50 hertz.
c. 30 V.
d. 60 hertz.
____ 112. Current from a battery is always
a. DC.
b. AC.
____ 113. Where do the electrons come from that produce heat and light in a light bulb?
a. the power company
b. the air
c. the wall plug
d. the bulb's wire filament
e. none of the above
____ 114. When we say an appliance uses up electricity, we really are saying that
a. electrons are taken out of the circuit and put somewhere else.
b. electron kinetic energy is changed into heat and other forms of energy.
c. the main power supply voltage is lowered.
d. current disappears.
e. electric charges are dissipated.
____ 115. Power outlets in our homes typically have a potential difference of
a. 30 V.
b. 120 A.
c. 60 A.
d. 240 V.
e. 120 V.
____ 116. When connected to a 110-volt power supply, how much current is in a light bulb that has a resistance of 220
ohms?
a. 0.5 A
b. 2.0 A
c. 110 A
d. 220 A
e. 24,200 A
____ 117. An electric heater is rated at 300 W for use in a 110-V circuit. The circuit breaker in the circuit can handle 12
A of current. How many heaters can be safely operated in the circuit?
a. 2
b. 3
c. 4
d. 5
e. more than 5
____ 118. A heater uses 21 A when connected to a 110-V line. If electric power costs 10 cents per kilowatt-hour in this
location, the cost of running the heater for 13 hours is _____.
a. $0.30
b. $0.75
c. $3.00
d. $7.51
e. none of the above
____ 119. A power line with a resistance of 9 ohms has a current of 80 A in it. The power dissipated in the line is
a. 360 W.
b. 720 W.
c. 1,440 W.
d. 57,600 W.
e. none of the above
____ 120. In order to form an electric circuit, you need to have
a. wires or conductors to connect everything.
b. a power source.
c. a light bulb or some resistance.
d. a complete path for the current.
e. all of the above
____ 121. In order for current to flow in a circuit, you must have
a. a switch that is open.
b. a complete path for the current.
c. two light bulbs in parallel.
d. two light bulbs in series.
e. all of the above
____ 122. Electrical resistance is measured in
a. volts.
b. amperes.
c. joules.
d. watts.
e. none of the above.
____ 123. A closed circuit is a circuit in which charge
a. can flow.
b. is prevented from flowing.
____ 124. When two light bulbs are connected in series, the
a. current through each light bulb is proportional to the resistance of the bulb.
b. same amount of current always flows through each bulb.
c. neither A nor B
____ 125. The symbol used to represent resistance in a schematic diagram is
a. two straight lines.
b. a single line that is broken and has a bend in it.
c. one straight line.
d. a zigzag line.
e. none of the above
____ 126. When resistors are put in series next to each other, their overall resistance is
a. the same as the resistance of one of the resistors.
b. larger than the resistance of any individual resistor.
c. smaller than the resistance of any of the resistors.
____ 127. When resistors are put in parallel with each other their overall resistance is
a. smaller than the resistance of any of the resistors.
b. larger than the resistance of any other resistor.
c. the same as the resistance of one of the resistors.
____ 128. As more lamps are put into a series circuit, the overall current in the circuit
a. stays the same.
b. increases.
c. decreases.
____ 129. As more lamps are put into a parallel circuit, the overall current in the circuit
a. increases.
b. stays the same.
c. decreases.
____ 130. When one light bulb in a parallel circuit containing several light bulbs burns out, the other light bulbs
a. do not burn at all.
b. burn brighter.
c. burn the same as before.
____ 131. Electrical devices in our homes are connected in
a. parallel.
b. series.
____ 132. Two lamps, one with a thick filament and one with a thin filament, are connected in series. The current is
greater in the lamp with the
a. thin filament.
b. thick filament.
c. Current is the same in each lamp.
____ 133. A 60-W light bulb is connected to a 12-V car battery. When another 60-W bulb is connected in parallel with
the first bulb, the battery's output energy
a. doubles.
b. halves.
c. remains the same.
____ 134. A 60-W light bulb and a 100-W light bulb are both connected in parallel to a 120-V outlet. Which light bulb
has more current in it?
a. the 100-W bulb
b. the 60-W bulb
c. Both have the same current.
____ 135. The current through two identical light bulbs connected in series is 0.25 A. The total voltage across both bulbs
is 120 V. The resistance of a single light bulb is
a. 24 ohms.
b. 48 ohms.
c. 240 ohms.
d. 480 ohms.
e. none of the above
____ 136. Moving electric charges will interact with
a. an electric field.
b. a magnetic field.
c. both A and B
d. none of the above
____ 137. Surrounding every moving electron is
a. an electric field.
b. a magnetic field.
c. both A and B
d. none of the above
____ 138. If you put a small compass in a magnetic field, the compass will
a. line up in a direction parallel to the magnetic field lines.
b. swing randomly.
c. line up in a direction perpendicular to the magnetic field lines.
d. seek electrical charge concentrations.
____ 139. Magnetic domains are
a. regions that may or may not be magnetized.
b. clusters of atoms randomly aligned.
c. regions of atoms magnetically aligned.
d. blocks of material.
____ 140. The reason a magnet can attract an unmagnetized nail is that
a. nails really are magnetized.
b. nails become temporarily magnetized in a magnetic field.
c. nails become permanently magnetized in a magnetic field.
d. a magnet can attract any metal object.
____ 141. When current passes through a wire, a magnetic field is created around the wire only if the
a. wire is absolutely straight.
b. wire is curved in a loop.
c. current makes a complete loop.
d. current comes from a battery.
e. A magnetic field is always created around the wire.
____ 142. A wire carrying a current is bent into a loop. The magnetic field is strongest
a. at the center of the loop.
b. at the edges of the loop.
c. where the loop is located.
____ 143. Loops of wire in a motor rotate because a
a. battery effectively pushes a loop around in the field.
b. current exerts a force on the loop, causing it to rotate.
c. magnetic field exerts forces on moving electrons in the loop.
d. magnet attracts stationary electrons in the wire.
e. none of the above
____ 144. The magnetic pole in the Northern Hemisphere is located
a. in Alaska.
b. in Canada.
c. at the geographic North Pole.
d. just north of the United States.
e. none of the above
____ 145. Which force field can increase a moving electron's speed?
a. electric field
b. magnetic field
c. both A and B
d. none of the above
____ 146. Which force field can accelerate an electron, but never change its speed?
a. electric field
b. magnetic field
c. both A and B
d. none of the above
____ 147. Changing the magnetic field intensity in a closed loop of wires induces
a. current.
b. voltage.
c. both current and voltage.
d. neither current nor voltage.
____ 148. A magnet is moved in and out of a coil of wire connected to a high-resistance voltmeter. If the number of
coils doubles, the induced voltage
a. is the same.
b. doubles.
c. quadruples.
d. halves.
e. none of the above
____ 149. A device consisting of a coil that is mechanically rotated in a stationary magnetic field is called
a. a motor.
b. a magnetic pole.
c. a generator.
d. a transformer.
e. a dipole.
____ 150. A generator is used to light a bulb. Energy for lighting the bulb actually comes from
a. a plug where the generator is connected to the wall.
b. a mechanical input to the generator.
c. the magnet in the generator.
d. the coil of wire.
e. none of the above
____ 151. If a magnet is pushed into a coil, voltage is induced across the coil. If the same magnet is pushed into a coil
with a greater speed
a. a larger voltage is induced.
b. a smaller voltage is induced.
c. the same voltage is induced.
____ 152. In an electromagnetic wave, the electric and magnetic fields are _____ to each other and _____ to the
direction of wave motion.
a. opposite, parallel
b. at right angles, perpendicular
c. parallel, at right angles
d. at right angles, parallel
____ 153. A transformer works because
a. electricity flows from a primary coil to a secondary coil.
b. electricity is induced in a rotating coil.
c. a changing magnetic field is transferred to a coil via an iron core.
d. electricity is transferred to a coil via an iron core.
____ 154. An electric motor and an electric generator are
a. entirely different devices.
b. very similar devices.
____ 155. A transformer transforms
a. magnetic field lines.
b. generators into motors.
c. voltage.
d. unsafe forms of energy into safe forms.
____ 156. A step-up transformer
a. doesn't change the voltage at all.
b. decreases voltage.
c. increases voltage.
____ 157. The principal advantage of AC power over DC power is that
a. AC voltage oscillates, whereas DC voltage does not.
b. lower voltages are used.
c. AC circuits multiply power more easily.
d. AC voltage can be transformed more easily.
e. AC circuits are safer.
____ 158. If a transformer increases AC voltage, it will also increase
a. energy.
b. magnetic field strength.
c. power.
d. current.
e. none of the above
____ 159. Light behaves as a
a. wave.
b. particle.
c. both A and B
d. none of the above
____ 160. The energy of a photon is directly proportional to its
a. speed.
b. amplitude.
c. period.
d. frequency.
e. wavelength.
____ 161. The photoelectric effect occurs when the incident light beam is
a. either dim or bright.
b. bright.
c. dim.
____ 162. Which of the following photons have the greatest energy?
a. blue light
b. yellow light
c. green light
d. red light
e. ultraviolet
____ 163. When light shines on a photosensitive material
a. electrons are always ejected.
b. electrons may be ejected.
c. protons are always ejected.
d. protons may be ejected.
e. none of the above
____ 164. The number of electrons ejected in the photoelectric effect depends on the light beam's
a. amplitude.
b. speed.
c. frequency.
d. intensity.
e. wavelength.
____ 165. A photosensitive surface is illuminated with both blue and violet light. The light that will cause more
electrons to be ejected is the
a. blue light.
b. violet light.
c. Both eject the same number.
d. Not enough information is given.
____ 166. The wavelength of a particle is called the
a. particle wavelength.
b. de Broglie wavelength.
c. Plank's constant.
d. particle's size.
e. photoelectric wavelength.
____ 167. Electron wavelengths, in general, are
a. the same as light wavelengths.
b. shorter than light wavelengths.
c. longer than light wavelengths.
____ 168. The energy states available to an electron are
a. quantized.
b. continuous.
____ 169. The ratio of a photon's energy to its frequency is
a. its wavelength.
b. its speed.
c. Planck's constant.
d. its amplitude.
e. none of the above
____ 170. Two photons have the same wavelength. They also have the same
a. energy.
b. frequency.
c. both A and B
d. none of the above
____ 171. Which of the following forms an interference pattern when directed towards two suitably spaced slits?
a. Light
b. Electrons
c. Sound
d. all of the above
e. none of the above
____ 172. Helium is four times as massive as hydrogen. Compared to the size of hydrogen, helium is
a. about twice as large.
b. smaller.
c. about four times as large.
d. about the same size.
____ 173. In quantum mechanics, one normally studies
a. what happens when light shines on a metallic surface.
b. the structure of light quanta.
c. the structure of atoms by treating light and particles as waves.
d. the mechanics of fast-moving objects such as cosmic rays.
____ 174. Planck's constant is a basic constant of nature that
a. formulates the relationship between mass and energy.
b. relates the energy of a photon to its momentum.
c. is the foundation of the correspondence principle.
d. sets an upper limit on the size of things.
e. sets a lower limit on the size of things.
____ 175. Orbital electrons do not spiral into the nucleus. This is because of
a. the large nuclear size compared to the electron's size.
b. the wave nature of the electron.
c. angular momentum conservation.
d. electromagnetic forces.
e. none of the above
____ 176. An excited atom decays to its ground state and emits a photon of green light. If, instead, the atom decayed to
an intermediate state, then the light emitted could be
a. blue.
b. red.
c. violet.
d. any of the above.
e. none of the above.
____ 177. An electron and a baseball move at the same speed. Which has the longer wavelength?
a. the baseball
b. the electron
c. Both have the same wavelength.
____ 178. An electron and a proton are traveling at the same speed. Which has a longer wavelength?
a. Both have the same wavelength.
b. the proton
c. the electron
____ 179. Which of the following has the longer wavelength?
a. A low-energy electron
b. A high-energy electron
c. Both have the same wavelength.
____ 180. The degree to which a system is predictable depends on knowledge of
a. whether or not the system is Newtonian or quantum.
b. initial conditions.
c. both A and B
____ 181. Which of the following is more chaotic?
a. weather
b. heat transfer between thermal conductors
c. electric current in an AC circuit
d. collision between two pool balls
____ 182. The force that holds the nucleus together is the
a. nucleonic force.
b. gravitational force.
c. electromagnetic force.
d. strong force.
e. none of the above
____ 183. X-rays are similar to
a. alpha rays.
b. beta rays.
c. gamma rays.
d. all of the above
e. none of the above
____ 184. Electrical forces within an atomic nucleus tend to
a. push it apart.
b. hold it together.
c. none of the above
____ 185. The type of radiation that will penetrate farthest into a material is
a. a beta ray.
b. a gamma ray.
c. an X-ray.
d. an alpha ray.
e. They all penetrate material the same distance.
____ 186. The two easily detectable products of the decay of a free neutron are
a. another neutron and an electron.
b. an alpha particle and an electron.
c. a proton and an electron.
d. a proton and a gamma ray.
e. none of the above
____ 187. Which experiences the greatest electrical force in an electric field?
a. an alpha particle
b. a gamma ray
c. a beta particle
d. a proton
e. same force for all of the above
____ 188. Deuterium
a. can become part of a molecule called heavy water.
b. is an isotope of hydrogen.
c. consists of one proton and one neutron.
d. is stable.
e. all of the above
____ 189. Large nuclei like uranium are radioactive because
a. they have too much mass.
b. they are too large for the strong force to counteract electrostatic repulsion.
c. there are too many protons.
d. they can hold extra particles, such as beta rays.
e. none of the above
____ 190. The time needed for half of a radioactive sample to decay is called its
a. transmutation time.
b. period.
c. decay period.
d. half-life.
____ 191. The half-life of most radioactive isotopes is about
a. 4.5 billion years.
b. 5700 years.
c. a few seconds.
d. a few years.
e. too variable for any generalization.
____ 192. Carbon-14 is radioactive and decays into
a. carbon-12.
b. oxygen-14.
c. carbon-13.
d. nitrogen-14.
e. none of the above
____ 193. Radioactive tracers can be used to help
a. engineers study how parts of a car withstand wear.
b. farmers use the proper amount of fertilizer.
c. public utility workers trace leaks in buried pipes.
d. doctors trace food as it moves through the body.
e. all of the above
____ 194. Carbon-14 is produced in the atmosphere primarily by
a. photosynthesis.
b. cosmic ray bombardment.
c. nitrogen bombardment.
d. plants and animals.
e. none of the above
____ 195. Carbon dating requires that the object being tested contain
a. sugar molecules.
b. inorganic material.
c. charcoal.
d. organic material.
e. none of the above
____ 196. When uranium (92 protons) ejects an alpha particle, the nucleus left behind has
a. 92 protons.
b. 91 protons.
c. 90 protons.
d. 89 protons.
e. 88 protons.
____ 197. All elements beyond uranium in the periodic table
a. do not exist.
b. are found naturally in the earth.
c. have no isotopes.
d. have relatively short half-lives.
e. none of the above
____ 198. When a nucleus emits a positron, its atomic number
a. doesn't change.
b. increases by 1.
c. decreases by 1.
____ 199. In order for an atom to decay to an element that is one greater in atomic number, it can emit
a. 1 positron and 2 beta particles.
b. 1 alpha particle and 3 beta particles.
c. 1 beta particle.
d. all of the above
e. none of the above
____ 200. You should limit the amount of extra radiation to which you are exposed, because
a. the body can only handle a certain amount of radiation in one lifetime.
b. radiation is harmful to the body.
c. radiation disrupts the body's intricately structured cell system.
d. all of the above
____ 201. A sample of a certain radioactive material has a half-life of 1 year. How much of this radioactive material will
be left at the end of 3 years?
a.
b.
c.
d.
e. All of it
____ 202. The half-life of carbon-14 is 5730 years. Suppose a bone was found that contains one fourth the concentration
of carbon-14 as a new bone of the same material. What is the approximate age of the bone?
a. 5,730 years.
b. 22,920 years.
c. 34,380 years.
d. 11,460 years.
e. none of the above
____ 203. The half-life of carbon-14 is 5730 years. If a 1-gram sample of old carbon is as radioactive as 1 gram of a
current sample, then the age of the old sample is
a. 1,910 years.
b. 716 years.
c. 17,190 years.
d. none of the above
____ 204. A certain radioactive isotope placed near a Geiger counter registers 160 counts per second. 32 hours later, the
counter registers 10 counts per second. What is the half-life of the isotope?
a. 8 hours
b. 16 hours
c. 24 hours
d. 32 hours
e. none of the above
____ 205. Uranium-235, uranium-238, and uranium-239 are different
a. isotopes.
b. ions.
c. elements.
d. none of the above
____ 206. When U-235 splits, it usually emits
a. no particles at all.
b. many electrons.
c. many protons.
d. one neutron.
e. three neutrons.
____ 207. Most nuclear power reactors work by
a. generating heat.
b. producing steam.
c. boiling water.
d. running turbines.
e. all of the above
____ 208. The release of energy in nuclear fission is consistent with the fact that uranium has
a. less mass per nucleon than either of the two fragments.
b. exactly the same mass per nucleon as the two fragments.
c. more mass per nucleon than either of the two fragments.
____ 209. The rate of a chain reaction in a nuclear fission reactor is controlled by
a. nucleons.
b. control rods.
c. uranium rods.
d. moderators.
____ 210. A mass spectrometer separates ions by using
a. a magnetic field.
b. an electric field.
c. a rotating drum.
d. an inertia driver.
e. none of the above
____ 211. The element with the least mass per nucleon is
a. uranium.
b. iron.
c. helium.
d. hydrogen.
e. none of these
____ 212. Nuclear fusion releases energy when
a. uranium emits a neutron.
b. uranium splits into two fragments.
c. very light nuclei fuse together.
d. heavy ions fuse together.
____ 213. Present-day research in nuclear fusion uses
a. ion beams.
b. ultra hot plasmas.
c. laser beams.
d. all of the above
e. none of the above
____ 214. Energy released by the sun results from atomic nuclei
a. combining.
b. breaking apart.
c. both A and B
d. none of the above
____ 215. The mass of a nucleus is exactly equal to the sum of the masses of its individual
a. neutrons.
b. protons.
c. nucleons.
d. all of the above
e. none of the above
____ 216. A nuclear proton has least mass in the nucleus of
a. hydrogen.
b. iron.
c. uranium.
d. oxygen.
e. same mass in all of the above.
____ 217. Fusing two helium nuclei yields
a. a net release of energy.
b. a net absorption of energy.
c. neither absorption nor release of energy.
____ 218. Splitting a lead nucleus would yield
a. a net release of energy.
b. a net absorption of energy.
c. neither absorption nor release of energy.
____ 219. If gold were used as nuclear fuel, it would be best
a. either fused or split.
b. split.
c. fused.
____ 220. When light nuclei such as hydrogen fuse to form helium energy is
a. released.
b. absorbed.
c. none of the above.
Problem
221. What is the weight of the air in a room that has dimensions of 30 m
20 m
4 m?
222. What would have to be the volume of a helium-filled balloon if it were to carry a 500-kg load aloft in air?
(Assume the density of air is 1.25 kg/m3 and the density of helium is 0.18 kg/m3.)
223. Three cubic meters of liquid air at standard temperature and pressure has a mass about 2700 kg. When this
much liquid air turns to gaseous air of density 1.25 kg/m3, what will its volume be?
224. How much lift will be exerted on airplane wings of 130 m2 area when the difference in air pressure below and
above is 5 percent of atmospheric pressure?
225. Mix 4 liters of 30°C water with 6 liters of 40°C water and you'll have water at what temperature?
226. A 53-g iron bar at 100°C is placed in 300 g of water at 30°C. If the specific heat capacity of iron is 0.11
cal/g°C, to what final temperature will the iron bar cool?
227. Consider 200 grams of water at 100°C. If one-eighth of the water rapidly evaporates, what will be the
temperature of the remaining water?
228. How many calories are released when 3 grams of 100°C steam turns to 0°C ice?
229. 1.0 g of steam at 100°C is added to 100 grams of ice at 0°C. What is the temperature of the resulting mixture?
230. 1800 calories of heat is removed from 7.0 grams of steam initially at 100°C. The H2O is in what form
afterward?
231. 4200 calories of heat is removed from 7.0 grams of steam initially at 100°C. In what form is the H2O
afterward?
232. 4900 calories of heat is removed from 7.0 grams of steam initially at 100°C. In what form is the H2O
afterward?
233. 3600 calories of heat is removed from 5.0 grams of steam initially at 100°C. In what form is the H2O
afterward?
234. Trace amounts of uranium in common granite heat it at a rate of 0.01 cal/kg per year. If a 42°C granite
boulder is thermally insulated so that no heat escapes, in how many years will it reach a melting point of
700°C? Assume the specific heat of granite is 200 cal/kg°C
235. An absolute temperature of 110 K is the same as what Celsius temperature?
236. The temperature of an object is raised by 70ºC. This is equivalent to what increase in its absolute
temperature?
237. At what temperature would the molecules of a gas have twice the average kinetic energy they have at a 26ºC
room temperature?
238. There is a type of power plant, known as OTEC, that operates on the temperature difference between warm
surface waters and cool deep waters. What is the Carnot efficiency of such a plant if the surface water is 25ºC
and the deep water is 4ºC?
239. 100,000 electrons are removed from a neutral plastic ball. What is its charge?
240. What is the magnitude of the force on an electron in an electric field of 400 N/C?
241. How much voltage is required to make 4 amperes flow through a 12-ohm resistor?
242. A battery does 18 J of work on 10 coulombs of charge. What voltage does the battery supply?
243. What is the power dissipated by a toaster that has a resistance of 40 ohms and is plugged into a 120-V outlet?
244. A certain bulb with a resistance of 240 ohms is labeled 60 W. For what voltage circuit was this bulb
designed?
245. Two identical resistors in parallel have an equivalent resistance of 7 ohms. If the same resistors were instead
connected in series, what would be the equivalent resistance?
246. A 30-V potential difference is applied across a series combination of an 8.0-ohm resistor and a 3.0-ohm
resistor. What is the current in the 8.0-ohm resistor?
247. A 60-V potential difference is applied across a parallel combination of a 10-ohm and a 20-ohm resistor. What
is the current in the 10-ohm resistor?
248. A 20.0-V potential difference is applied across a parallel combination of a 60.0-ohm and a 10.0-ohm resistor.
What is the current in the 10.0-ohm resistor?
249. A step-up transformer has 40 turns on its primary and 100 turns on its secondary. When the primary is
supplied with an alternating current at 140 V, what is the voltage across the secondary?
250. A step-up transformer has 250 turns on its primary and 500 turns on its secondary. When the primary is
connected to 120 V and the secondary is connected to a floodlight that draws 5 A, what is the power output?