Q1 p106 ch16. Wave Motion

            1.  What is the wavelength of transverse wave with a velocity of 15 meters per second and a frequency of 5.0 hertz?

                        A. 3.0 m

                        B. 10 m

                        C. 20 m

                        D. 45 m

            2. The wave equation is  y=f(x-0.3t) where x is in meters and t is in seconds and 0.3 is m/s.  In the standard coordinate system with positive x to right, negative to left, and positive y upward, is this wave traveling to the right or left?

                        A. right

                        B. left

                        C. Wrong!  The wave is traveling upward!

            3. In the wave function y=f(x-0.3t) in the preceding question, the speed of the wave is

                        A. x

                        B. y

                        C. 0.3

                        D. t

            4. In the wave function y=A sin ((2pi/lambda)(x-vt)), the frequency of the wave is

                        A. A

                        B. y/A

                        C. v/lambda

                        D. lambda/v

            5. A piano string of density 0.005 kg/m is under tension 1350N.  Find the speed at which a transverse wave will travel along the string.

                        A. 260 m/s

                        B. 520 m/s

                        C. 1040 m/s

                        D. 270000 m/s

                        E. 0.005 m/s

 

 

 

Q02 p106 ch17. SoundWaves

            1. The foghorn of a ship echoes off an iceberg in the distance. If the echo is heard 5.00 seconds after the horn is sound, and the air temperature is -50.00C, how far away is the iceberg?

                        A. 200 m

                        B. 750 m

                        C. 825 m

                        D. 900 m

 

            2. What is the intensity, in W/m2, of sound with a sound level of 20 dB?

                        A. 10-12 W/m2

                        B. 10-10 W/m2

                        C. 1 W/m2

                        D. 10 W/m2

 

            3. What is the sound level in dB of a wave with an intensity of 10-3 W/m2?

                        A. 30 dB

                        B. 60 dB

                        C. 90 dB

                        D. 120 dB

 

            4. The sound pressure variation is 58 N/m^2 of a sound wave, the density of air is 1.29 kg/m^3 and the speed of sound is 331 m/s.  What is the intensity of the sound wave?

                        A. 0.5 W/m^2

                        B. 0.5 J/m^2

                        C. 1 W/m^2

                        D. 4 J/m^2

                        E. 4 W/m^2

 

            5. A sound source emits at 400 Hz with a speed of 343 m/s.  An observer runs toward the source at 30 m/s and the source is moving away from the observer at 30 m/s.  What the frequency of the source as heard by the observer?

                        A. 400 Hz

                        B. 477 Hz

                        C. 954 Hz

                        D. 0 Hz

Q3 Ph106ch18.Superposition&StandingWaves

1.      Two pulses, exactly out of phase, travel toward each other along a string as indicated in the figure.The phenomenon that occurs when the pulses meet is called____.

                        A. refraction.

                        B. reflection.

                        C. diffraction.

                        D. interference.

 

            2.  If two identical sound waves interact in phase, the resulting wave will have a

                        A. shorter period.

                        B. 2xlarger amplitude.

                        C. higher frequency.

                        D. greater velocity.

                        E. 4xlarger amplitude

 

            3.  If two frequencies emitted from two sources are 48 and 54 vibrations per second, how many beats per second are heard?

                        A. 3

                        B. 6

                        C. 9

                        D. 12

 

            4. A stretched string of length L=10cm is observed to vibrate in two equal amplitude segments.  It is tied at the ends and is driven by a 480 Hz oscillator.  What is the wavelength of the wave?

                        A. 1cm

                        B. 10cm

                        C. 50cm

                        D. 150cm

 

                                                                                         Ph106Q04.ch23a.ElectricCharge(Serway)

 

   1     Two electrically neutral materials are rubbed together. One acquires a net positive charge.

         The other must have

 

              A   lost electrons.

              B    gained electrons.

              C   lost protons.

              D   gained protons.

 

   2     What is the charge on a body that has an excess of 20 electrons?

 

              A   -3.2 x 10-18C

              B    -1.6 x 10-18C

              C   3.2 x 10-19C

              D   2.4 x 10-19C

 

   3     Which electric charge is possible?

 

              A   6.02 x 10-23 C

              B    3.2 x 10-19 C

              C   2.4 x 10-19 C

              D   8.0 x 10-20 C

 

   4     In a solid metal conductor, electric current is the movement of

 

              A   electrons only.

              B    protons only.

              C   nuclei.

              D   electrons and protons.

 

Q5 chap. 23b, Elec. Field  ph106

 

   1     Which diagram best represents the electric field lines around two oppositely charged

         particles?

 

              A

 

             

 

 

       B

 

 

 

C

 


             

 D

 

 

 

 

 

 

 

2 Which of the following is a vector quantity?

A    Electric charge      B   Electric energy        C   Electric power        D    Electric field

 

   3     Assume two point charges, A=2.0 x 10-4C and B = -4.0 x 10-4C, with A at coordinates x=0 m, y=0 m and B at 0 m, 6.0 m. What are the components (x,y) of the electrostatic force

         exerted on point A?

              A   (0, 20) N

              B    (0, -20) N

              C   (+20 , 0) N

              D   (-20,0) N

 

   4     Assume two point charges, A=2.0 x 10-4C and B = -4.0 x 10-4C, with A at coordinates x=0

         m, y=0 m and B at 0 m, 6.0 m. What are the components (x,y) of the electrostatic FIELD

         exerted on point A?

              A   (0,  1x10^5) N/C

              B    (0,  -1x10^5) N/C

              C   (+1x10^5 , 0) N/C

              D   (   1x10^5,  0) N/C

p106.  q6.  ch23c.  Electric Field (Continuous Charge Distr)

 

1.      The linear charge density on an insulating rod of length "L" with charge "Q" distributed uniformly over it is

 

                        A. Q/L3

                        B. Q/L2

                        C. Q/L

                        D. QL

 

 

            2.  Assume the charged rod in the previous question points along the x axis and is off to one side with one end positive a distance A from the origin. For a point along the axis at the origin, the contribution of a small bit of charge dQ on the rod to the x and y components of the electric field at the origin, (Ex, Ey), are

                        A. (kdQ/x, kdQ/x)

                        B. (kdQ/x2, kdQ/x2)

                        C. (kdQ/x, 0)

                        D. (kdQ/x2, 0)

 

            3.  The bit of charge on the rod in the first question, dQ, is equal to

A. the linear charge density on the rod, Q/L

B. the linear charge density times dx where dx is a small increment of length along the rod, which gves Qdx/L

C. linear charge density times (dx)2 where dx is a small increment of length along the rod

D. the linear charge density /(dx)2 where dx is a small increment of length along the rod

 

            4. If the rod in the first question of length L is located on the +x axis with one end at a positive distance A from the origin, the x component of the electric field at the origin is the integral of k(Q/L)dx/x2

A. from -L/2 to +L/2                B. from -L to +L

C. from A to L+A       D. from -L to A

 

Q7 p106 ch24. Gauss' Law

            1.  For all this quiz's questions, consider a cylinder of length, L, whose ends are two small disks of radius, "r". Assume a uniformly charged sheet cuts perpendicularly mid way through the cylinder walls creating a uniform E field 90 degrees to the disk ends. The electric flux is

                        A. zero through the cylinder wall and 2(pi r2)E through the two ends.

                        B. zero through the cylinder wall and zero through the two disk ends.

                        C. (2 pi r L E) through the cylinder wall and zero through the two

disk ends.

 

            2. Recall that an large insulating sheet of charge surface density, "S", slices this quiz's cylinder 90 degrees into two equal halves. The amount of charge inside the cylinder is

                        A. pi x S

                        B. pi x r x S

                        C. pi x r2 x S

                        D. pi x r3 x S

 

            3.  Gauss' law says that the electric flux through a closed surface is equal to (charge enclosed inside)/epsilon0 . Setting the electric flux through the cylinder ends to the (charged inside)/epsilon0 , we obtain

                        A. 2x(pi x r^2 x E) = pi x r^2 x S/epsilon0

                        B. (pi x r^2 x E) = pi x r2 x S/epsilon0

                        C. 2x(pi x r^2 x E) = 0

 

            4.  Using the results of the previous question, the electric field due to a large uniformly charged sheet is E =

                        A. kS/r2

                        B. S/epsilon0

                        C. S/(2 x epsilon0)

                        D. S x pi x r2/(2 x epsilon0)

Q8 p106 ch25. ElectricPotential

            1. Consider two charges, Q1=-9x10-6 C and Q2=-5x10-5C, which are 0.4m apart.  What is the electric potential at Q1?  There are no other charges besides Q1 and Q2.

                        A. -1.12x10^6 J/C

                        B. 1.12x10^6 J/C

                        C. -1.12x10^6 J/C

                        D. 1.12x10^5 J/C

            2. Consider same two charges, Q1=-9x10-6 C and Q2=-5x10-5C, the same 0.4m apart.  What total kinetic energy do the two charges have if they fell to 0.4m from an infinite distance apart?

                        A. 10.1 J

                        B. -10.1 J

                        C. 101 J

                        D. -101 J

 

            3. Which of the following is a vector quantity?

                        A. Electric charge

                        B. Electric energy

                        C. Electric power

                        D. Electric field intensity

 

            4. What is the potential difference between point A and point B if 10 J of work is required to move a charge of 4.0 C from one point to the other?

                        A. 0.4 V

                        B. 2.5 V

                        C. 14 V

                        D. 40  V