(navigation image)
Home American Libraries | Canadian Libraries | Universal Library | Community Texts | Project Gutenberg | Biodiversity Heritage Library | Children's Library | Additional Collections
Search: Advanced Search
Anonymous User (login or join us)
Upload
See other formats

Full text of "Test Booklet 4 - Light"

The Project Physics Course 



Tests 



4 



Light and Electromagnetism 



Digitized by the Internet Archive 

in 2010 with funding from 

F. James Rutherford 



http://www.archive.org/details/testbooklet4ligh00fjam 



The Project Physics Course 



Tests 



UNIT 



4 Light and Electromagnetism 



A Component of the 
Project Physics Course 




Distributed by 

Holt, Rinehart and Winston, Inc. 

New York-Toronto 



This publication is one of the many instructional materials 
developed for the Project Physics Course. These materials 
include Texts, Handbooks, Teacher Resource Books, 
Readers, Programmed Instruction Booklets, Film Loops, 
Transparencies, 16mm films and laboratory equipment. 
Development of the course has profited from the help of 
many colleagues listed in the text units. 



Directors of Harvard Project Physics 

Gerald Holton, Department of Physics, Harvard 

University 
F. James Rutherford, Chairman of the Department 

of Science Education, New York University, New York 
Fletcher G. Watson, Harvard Graduate School of 

Education 



Picture Credit 

Cover photo: (Close-up view of the 210-foot-in-diaineter tracking and com- 
munication antenna, Goldstone, California). Courtesy of Jet 
Propulsion Laboratory, California Institute of Technology 
and National Aeronautics and Space Administration. 



Copyright © 1970, Project Physics 

All Rights Reserved 

ISBN 0-03-084818-0 

4567 039 9876543 

Project Physics is a registered trademark 



TEST A 



Directions 

This test consists of fifteen multiple-choice questions and seven problem-and-essay questions, 
divided into two groups. Answer ALL multiple-choice questions by marking the letter correspond- 
ing to the one best answer. Answer THREE of the problem-and-essay questions from Group One 
and ONE from Group Two. Spend about 15 minutes on the multiple-choice questions, 5 minutes 
on each of the problem-and-essay questions from Group One and 10 minutes on the problem-and- 
essay question from Group Two. 

Equations that may be useful in this test are given on the last page of this booklet. 

MULTIPLE-CHOICE QUESTIONS 



1. A person whose eyes are located at point P is looking into the mirror. Which of the numbered 
cards can he see reflected in the mirror? 



MIRROR 



A. 1 and 4 

B. 2 and 3 

C. 1,2 and 3 

D. 1, 2, 3 and 4 



P« 



12 3 

4 



2. A point charge +Qi exerts an electrostatic force F on point charge +Q2 3 centimeters away. 
If the charges are placed 6 centimeters apart, the magnitude of the electrostatic force +Qi 
exerts on +Q2 will be 

A. 4F 

B. 2F 

C. F 

D. F/2 

E. F/4 

3. A narrow beam of light emerges from a block of ordinary glass in the direction shown in the 
diagram. Which arrow in the diagram best represents the path of the beam within the glass? 




Glass 



Air 



4. Two spheres, A and B, are 4 meters apart. A charge of 2Q coulombs is distributed over sphere 
A and a charge of Q coulombs is distributed over sphere B. (See sketch.) 



4m- 



2Q 



<i 



Q 



How does the magnitude of the force exerted by A on B compare with the magnitude of the force 
exerted by B on A? 

A. The force on A is 4 times the force on B. 

B. The force on A is 2 times the force on B. 

C. The force on A is the same as the force on B. 

D. The force on A is 1/2 the force on B. 

E. The force on A is 1/4 the force on B. 



5. Which of the arrows indicates the direction of the electric field at point P due to the stationary 
charges +Q and -Q? 

c 



-Q» 



B 




D 



-E 



6. The first definite evidence that light moves at a finite speed was found by 

A. Galileo. 

B. Rbmer. 

C. Huygens. 

D. Young. 

7. In a vacuum, electromagnetic radiations such as radio waves, light, x rays and gamma rays have 
the same 



A. wave length. 

B. frequency. 

C. period. 

D. speed. 

E. amplitude. 



Newton's synthesis of terrestrial and celestial mechanics incorporated the work of Kepler and 
Galileo. In a similar way, the work of Oersted and Faraday was incorporated in the synthesis 
made by 



A. Ampere. 

B. Hertz. 

C. Maxwell. 

D. Gilbert. 



9. The direction of the electric field in a plane electromagnetic wave is 

A. perpendicular to the magnetic field and in the direction of the wave's propagation. 

B. perpendicular to the magnetic field and perpendicular to the direction of the wave's 
propagation. 

C. parallel to the magnetic field. 



10. Power is 

A. work. 

B. electrical current. 

C. the rate of flow of electric charge. 

D. the rate of doing work. 



11. A transformer changes 

A. electrical energy into mechanical energy, 

B. mechanical energy into electrical energy. 

C. high voltage dc to low voltage dc. 

D. low voltage ac to high voltage ac. 



12. An example of electromagnetic induction is the 

A. magnetic field about a conductor carrying a current. 

B. force between a magnet and a wire carrying a current. 

C. production of a current in a wire owing to a changing magnetic field. 

D. force between two wires carrying electric currents. 

E. depositing of an element at the cathode of an electrolytic cell. 



/ 



Questions 13, 14 and 15 list the names of scientists who made significant contributions to the 
study of electromagnetic phenomena. Select the statement that best describes a contribution of 
each of the scientists. 

A. Two current-carrying wires exert forces on each other. 

B. An electric field changing with time generates a magnetic field. 

C. An electric current exerts a force on a magnet. 

D. A magnetic field changing with time can cause a current to flow in a wire. 

13. Maxwell 

14. Ampere 

15. Faraday 

PROBLEM-AND-ESSAY QUESTIONS 
Group One 
Answer THREE of the following five questions. Allow about 5 minutes each. 

1. Explain how the results of Hertz's experiment supported Maxwell's theory of electro magnetism. 

2. What is one of the predictions Maxwell made on the basis of his electromagnetic wave theory? 

3. The starter motor in a car for a short time draws a fairly steady current of 100 amperes from a 
12-volt battery to turn over the engine. How many watts of power does this represent? 

4. Describe two examples of experimental evidence that support the contention that a magnetic 
field exists in the space around a current-carrying wire. 

5. Consider two bodies with charges +Q and -Q, and a third body at P with charge +q, as shown in 
the diagrams below. In each of the diagrams draw an arrow at P pointing in the direction of the 
resultant force +q experiences due to +Q and -Q. 



© © 



+ Q \ 



2m 



+ Q 






N^ 1.5m 




^N 




N 




^s P 




:® 




x" -^q 




/ 




/ 




.-^ 1.5m 



©-r.--t ©■ 

-Q ^ -Q 



PROBLEM-AND-ESSAY QUESTIONS 
Group Two 
Answer ONE of the following two questions. Allow about 10 minutes. 

6. With the aid of a diagram showing the essential parts of a transformer, explain how a trans- 
former works. 

7. Young's double-slit experiment demonstrated the interference of light waves. With the aid of a 
diagram describe how the experiment is done and explain why interference is observed. 



TEST B 



Directions 

This test consists of fifteen multiple-choice questions and seven problem-and-essay questions, 
divided into two groups. Answer ALL multiple-choice questions by marking the letter correspond- 
ing to the one best answer. Answer THREE of the problem-and-essay questions from Group One 
£ind ONE from Group Two. Spend about 15 minutes on the multiple-choice questions, 5 minutes 
on each of the problem-and-essay questions from Group One and 10 minutes on the problem-and- 
essay question from Group Two. 

Equations that may be useful in this test are given on the last page of this booklet. 



MULTIPLE-CHOICE QUESTIONS 

1. Which of the following graphs best represents the way the force one small charged body exerts 
on another changes when the distance between their centers is changed? 






distance 



distance 



distance 



distance 



distance 



2. ALL EXCEPT ONE of the following satisfy the definition of a field as given in the text. Find 
the exception. 

A. water temperature in Lake Michigan 

B. density of smoke in the air above New York 

C. noise level in a stadium during a baseball game 

D. depth of snow on the ground during a blizzard 

E. the total number of babies bom in the United States during 1965 

3. Which of the following is not an electromagnetic wave phenomenon? 



A. 


radar 


B. 


ultraviolet light 


C. 


sound 


D. 


x-radiation 



4. A coulomb is a unit of ' 

A. resistance. 

B. power. 

C. current. 

D. potential difference. 

E. charge. 

Questions 5, 6 and 7 list the names of scientists who made significant contributions in the study 
of light. Select the statement from the list below that best describes the contribution of the particu- 
lar scientist. 

A. showed that light exhibits the phenomenon of interference 

B. found that color is not an inherent property of an object, but depends on how the object 
reflects and absorbs the various colored rays that strike it 

C. invented a plastic sheet that would polarize light 

D. developed a mathematical wave theory of light 

5. Young 

6. Fresnel 

7. Newton 

8. In a vacuum, electromagnetic radiations such as radio waves, light, x rays and gamma rays have 
the same 



A. 


wavelength. 


B. 


frequency. 


C. 


period. 


D. 


speed. 


E. 


amplitude. 



9. A narrow beam of light strikes a block of ordinary glass at the angle shown in the diagram. 
Which arrow in the diagram best represents the direction of the beam within the glass? 




Question 10 refers to the following diagram and statement. 

P A B ^ positively charged pith ball is located at point P. 

^-^ The electric field (magnitude and direction) at 

Kjy * ^ * point A due to the charge at P is represented by 

the arrow shown. 

10. Which vector best represents the electric field at point B due to the charge at P? 

A. ► 

B. >■ 

C. ► 

D. > 

E. ^ 

11. Gravitational and electrostatic (coulomb) forces are similar in many ways but differ in others. 
Which one of the following statements is not true for both gravitational and electrostatic forces? 

A. The force varies at l/R^ . 

B. The force depends upon the quantity (mass or charge) on which the force acts. 

C. The force can be attractive and repulsive. 

D. The force law can be tested in the laboratory. 

o 

12. The Angstrom (A) is a unit of 

A. mass. 

B. time. 

C. speed. 

D. length. 

13. The direction of the electric field in a plane electromagnetic wave is 

A. perpendicular to the magnetic field and in the direction of the wave's propagation. 

B. perpendicular to the magnetic field and perpendicular to the direction of the wave's 
propagation. 

C. parallel to the magnetic field. 

14. The wavelength of visible light is most nearly the same as 

A. the length of a football field. 

B. your height. 

C. the diameter of an apple. 

D. the diameter of a pencil. 

E. the thickness of a soap bubble. 



15. A conclusion that could be drawn from the experiment of Michelson and Morley was that 

A. the speed of light is greater in a vacuum than in glass. 

B. light is an electromagnetic radiation. 

C. the earth moves through the ether. 

D. light consists of particles, not waves. 

E. there is no ether. 



PROBLEM-AND-ESSAY QUESTIONS 
Group One 
Answer THREE of the following five questions. Allow about 5 minutes each. 

1 . The introduction of inexpensively transmitted electrical power late in the nineteenth century 
had profoimd effects on the structure of American society. State and discuss briefly two of 
these effects. 

2. Discuss the objection to Newton's theory of color raised by nature philosophers such as Schell- 
ing and Goethe. 

3. Describe the term "field" as it is used in physics. 

4. Describe one property of x rays that makes them suitable for medical diagnosis of bone 
fractures. 

5. State one reason for the conclusion that electromagnetic waves carry energy. 

Group Two 
Answer ONE of the following two questions. Allow about 10 minutes. 

6. Why is the sky blue? 

7. Consider a wire loop between magnetic poles, as shown below. Discuss the physical principles 
involved when this apparatus is used as a generator of electric current. 




TEST C 



Directions 

Answer ALL forty multiple-choice questions by marking the letter corresponding to the one best 
answer. 

Equations that may be useful in this test are given on the last page of this booklet. 



1 . A unit of electric potential difference is the 

A. ampere. 

B. ohm. 

C. volt. 

D. joule. 

E. coulomb. 

2. Arrange the following units of length in order of increasing magnitude. 

1 . centimeter 

2. angstrom 

3. meter 

The correct arrangement is 

A. 1,2,3. 

B. 2,3,1. 

C. 3,1,2. 

D. 2,1,3. 

E. 3,2,1. 

3. The equations that led to the prediction that light is an electromagnetic phenomenon were 
derived by 

A. Coulomb. 

B. Oersted. 

C. Faraday. 

D. Maxwell. 

E. Ampere. 



10 



4. ALL EXCEPT ONE of the following satisfy the definition of a field as given in the text. Find 
the exception. 

A. water temperature in Lake Michigan 

B. density of smoke in the air above New York 

C. noise level in a stadium during a baseball game 

D. depth of snow on the ground during a blizzard 

E. the total number of babies bom in the United States during 1965 

5. Which one of the following statements is correct? 

A. Electricity and magnetism are unrelated phenomena. 

B. Magnets can produce electric currents, but electric currents cannot produce magnetic 
fields. 

C. Magnets can produce electric currents and electric currents can produce magnetic fields. 

D. Electric currents cannot produce magnetic fields. 

E. Electricity and magnetism are identical properties of lodestones. 



6. Two uncharged conducting spheres are suspended by nylon threads and touch each other. With 
a positively charged rod held near sphere 1 the two spheres separate. The charges on the two 
spheres will be 





Sphere 1 


Sphere 2 


A. 


none 


positive 


B. 


negative 


positive 


C. 


none 


none 


D. 


negative 


none 



c^^ 



00 

1 2 



7. The electric field vector at a point in an electrostatic field indicates 

1. the magnitude of the electrostatic force exerted per unit charge at that point. 

2. the direction of the electrostatic force exerted per unit charge at that point. 

3. the electric charge at that point. 

Which of the above correctly describe (s) a property of the electric field vector? 

A. 3 only 

B. 1 and 2 only 

C. 1 and 3 only 

D. 2 and 3 only 

E. 1, 2 and 3 



11 



A narrow beam of light emerges from a block of ordinary glass in the direction shown in the 
diagram. Which arrow in the diagram best represents the path of the beam within the glass? 

A 
B 




Glass 



Air 



9. Newton's synthesis of terrestrial and celestial mechanics incorporated the work of Kepler and 
Galileo. In a similar way, the work of Oersted and Faraday was incorporated in the synthesis 
made by 

A. Ampere. 

B. Hertz. 

C. Maxwell. 

D. Gilbert. 

10. A glass prism separates white light into the colors of the spectrum because 

A. light is reflected inside the prism. 

B. different frequencies of light move with different speeds in the prism. 

C. different frequencies of light superpose in the prism. 

D. electromagnetic energy is dissipated inside the prism. 

11. Which of the following graphs best represents the way the force one small charged body exerts 
on another changes when the distance between their centers is changed? 





distance 



distance 



distance 



distance 



distance 



12. Which of the following graphs best represents the force on a charged particle moving across a 
uniform magnetic field when the particle's speed increases? 

A B C D E 





speed 



speed 



speed 



speed 



speed 



12 



13. A conclusion drawn from the experiment of Michelson and Morley was that 

A. the speed of light is greater in a vacuum than in glass. 

B. light is an electromagnetic radiation. 

C. the earth moves through the ether with the speed of light. 

D. light consists of particles, not waves. 

E. there is no ether. 

14. Which of the following is not an electromagnetic wave phenomenon? 

A. radar 

B. ultraviolet light 

C. sound 

D. x-radiation 

15. Which of the following produce(s) a magnetic field? 

1 . an electric current in a wire 

2. a moving charged particle 

3. a changing electric field 

A. 1 only 

B. 1 and 2 only 

C. 1 and 3 only 

D. 2 and 3 only 

E. 1,2 and 3 

16. In a vacuum, electromagnetic radiations, such as radio waves, light, x rays and gamma rays 
have the same 

A. wavelength. 

B. frequency. 

C. period. 

D. speed. 

E. amplitude. 

17. P watts of power are dissipated in the form of heat when a current I flows through a heater coil 
whose resistance is R. If the current through the coil is doubled, how much power will be dis- 
sipated in the form of heat? 

A. 1/4 P watts 

B. 1/2 P watts 

C. P watts 

D. 2P watts 

E. 4P watts 



13 



18. Gravitational and electrostatic (Coulomb) forces are similar in many ways but differ in others. 
Which one of the following statements is not true for both gravitational and electrostatic forces? 

A. The force varies as 1/R^ . 

B. The force depends upon the quantity (mass or charge) on which the force acts. 

C. The force can be attractive and repulsive. 

D. The force law can be tested in the laboratory. 

19. The direction of the electric field in a plane electromagnetic wave is 



A. perpendicular to the magnetic field and perpendicular to the direction of the wave's 
propagation. 

B. perpendicular to the magnetic field and in the direction of the wave's propagation. 

C. parallel to the magnetic field. 



20. A wire carrying a large and constant electric current 
passes through the center of and perpendicular to a 
piece of cardboard, as shown at right. If iron filings 
are sprinkled on the cardboard, how will they arrange 
themselves? 









21. A person whose eyes are located at point P is looking into the mirror. Which of the numbered 
cards can he see reflected in the mirror? 

MIRROR 

A. 1 and 4 

B. 2 and 3 

C. 1,2 and 3 

D. 1,2, 3 and 4 ,4 



3 E 



22. The wave and particle models of light predict contradictory values of the velocity of light when 
used to explain 

A. reflection of light. 

B. refraction of light. 

C. polarization. 

D. superposition. 



14 



23. Consider the following: 

1. a wire loop surrounding a wire with a steady current. 

2. a magnet dropping through a wire loop. 

3. a stationary charged sphere at the center of a wire loop. 

In which of the above is a current produced in the wire loop? 

A. 1 only 

B. 2 only 

C. 3 only 

D. 1 and 3 only 

E. 2 and 3 only 

24. Which of the following is the chief physical principle on which the operation of an electric 
generator depends? 

A. A current is induced in a wire moving through a magnetic field. 

B. The electric field strength varies as the inverse square of the distance from a charge. 

C. Two current-carrying wires exert forces on one another. 

D. An alternating current produces electromagnetic radiation. 

o 

25. The Angstrom (A) is a unit of 

A. mass. 

B. time. 

C. speed. 

D. length. 

26. Which of the following could you measure to find your true motion through space? 

A. apparent speed of light 

B. speed of the motion relative to the ether 

C. speed of the motion relative to some stationary object 

D. none of the above 

27. A vertical wire hidden in a wall is carrying a direct current. What piece of equipment might 
help you find the location of the wire? 

A. transformer 

B. dc generator 

C. compass 

D. radio receiver 



15 



28. Two identically charged small spheres are at a distance r meters apart. If the distance is 
doubled to 2r meters, the force exerted on each sphere will 

A. change to 4 times the original value. 

B. change to 2 times the original value. 

C. not change. 

D. change to 1/2 the original value. 

E. change to 1/4 the original value. 



29. In the apparatus shown at right, a beam of 
positively charged particles is directed hori- 
zontally into the field between two magnets. 
What is the effect of the magnetic field? 

A. The particles continue in the same 
direction with the same speed. 

B. The particles are accelerated toward 
the S magnetic pole. 

C. The particles are accelerated toward 
the N magnetic pole. 

D. The particles are accelerated upward. 





Questions 30, 31 and 32 list the names of scientists who made significant contributions in the 
study of light. Select the statement from the list below that best describes the contribution of the 
particular scientist. 

A. Light exhibits the phenomenon of interference. 

B. Color is not an inherent property of £m object, but depends on how the object reflects 
and absorbs the various colored rays that strike it. 

C. Invented a plastic sheet that would polarize light. 

D. Developed a mathematical wave theory of light. 

30. Young 

31. Fresnel 

32. Newton 

33. Three identical metal balls A, B and C are mounted on insulating rods. Ball A has a charge +q, 
while balls B and C are uncharged. Ball A is brought into contact momentarily with ball B, and 
then with hall C. At the end of this experiment, the charge on ball A will be: 

A. +q. 

B. +q/2. 

C. +q/3. 

D. +q/4. 

E. No charge remains on A. 



16 



Questions 34, 35 and 36 list the names of scientists who made significant contributions to the 
study of electromagnetic phenomena. Select the statement that best describes a contribution of the 
particular scientist. 

A. Two current-carrying wires exert forces on each other. 

B. An electric field changing with time generates a magnetic field. 

C. An electric current exerts a force on a magnet. 

D. A magnetic field changing with time can cause a current to flow in a wire. 

34. Maxwell 

35. Ampere 

36. Faraday 

37. An electric motor that draws a two-ampere current when operating at 110 volts can do work at 
the rate of 

A. 55 watts. 

B. 110 watts. 

C. 220 watts. 

D. 440 watts. 

38. Which one of the following scientists first demonstrated experimentally that the earth behaves 
like a large magnet? 

A. Gilbert 

B. Oersted 

C. Faraday 

D. Maxwell 

E. Ampere 

39. A charged particle moves through a uniform magnetic field. The effect of the field can change 
the particle's 

A. velocity. 

B. speed. 

C. energy. 

40. A transformer can be used to change 

A. electrical energy into mechanical energy. 

B. mechanical energy into electrical energy. 

C. high voltage dc to low voltage dc. 

D. low voltage ac to high voltage ac. 



17 



TEST D 



Directions 

This test consists of eight questions in two groups. Answer only FOUR of the five questions in 
Group One, and only TWO of the three questions in Group Two. Spend about 5 minutes on each of 
the questions from Group One, and 10 minutes on each of the questions from Group Two. 

Equations that may be useful in this test are given on the last page of this booklet. 



Group One 
Answer only FOUR of the five questions in this group. Allow about 5 minutes each. 

1. Describe any changes that occur in the velocity, wavelength, and frequency of light as it passes 
from air into a block of glass. 

2. Explain why there are belts of rapidly moving charged particles (Van Allen belts) around the 
earth. 

3. Was the postulation of an ether a necessary part of Maxwell's electromagnetic theory? Explain 
briefly . 

4. Describe two similarities between x rays and radio waves. 

5. Describe how to determine whether a given material is an electrical insulator or conductor. 

Group Two 
Answer only TWO of the three questions in this group. Allow about 10 minutes each. 

6. Three charged objects A, B and C are situated as indicated in the diagram below. Use Coul- 
omb's law to calculate the net electrostatic force on C. 

(k = 9x 10^ 



Coulomb^ 



I- 



1 m 



10 
(i)A (•)C (i)B 

q^ = +1 X 10-^ C qc = -1 X 10"^ C qg = +2 x 10" 



18 



7. Why £ire brilliantly colored sunsets sometimes seen in highly industrial areas where there is the 
problem of air pollution? 

8. What are the two main assumptions of Einstein's special theory of relativity? 



19