Which one of the pipes emits sound with the lowest frequency? Which one of the pipes emits sound with the next lowest frequency?

Transcription

1 The figures show standing waves of sound in six organ pipes of the same length. Each pipe has one end open and the other end closed. Warning: some of the figures show situations that are not possible Which one of the pipes emits sound with the lowest frequency? : 1 : 2 C: 4 D: 5 Which one of the pipes emits sound with the next lowest frequency? : 1 : 2 C: 4 D: 5 Which one of the pipes emits sound with the highest frequency? : 2 : 3 C: 4 D: 6

2 Compared with the sound you hear from the siren of a stationary fire engine, the sound you hear when the fire engine approaches you has an increased. speed.. frequency. C. oth of these. D. Neither of these. The electric field cannot exist in a vacumm. True.. False. Complete the following statement: simple series circuit contains a resistance R and an ideal battery. If a second resistor is connected in parallel with R, ) the voltage across R will decrease. ) the current through R will decrease. C) the total current through the battery will increase. D) the equivalent resistance of the circuit will increase.

3 n electron is moving at high speed through a field-free region. In enters (and soon exits) a region in which the electric field points up. Which path best represents the path of the electron? uniform E field C D uniform E field

4 Three charges all carry the same magnitude of charge Q, but with different signs as shown below. Q +Q 1 2 +Q 3 Which of the arrows is in the direction of the net force on charge 2? C D

5 Three charges all carry the same magnitude of charge Q, but with different signs as shown below. +Q +Q 1 2 Q 3 Which of the arrows is in the direction of the net force on charge 2? C D

6 Two pith balls of identical mass and shape are suspended from the ceiling by nonconducting strings. all 1 is given a charge of q 1 =Q and ball 2 is given a charge q 2 =3Q. Which of the below pictures best displays the final positions of these balls? initial situation 1 2 Q 3Q C D

7 negatively charged rod approaches a previously neutral conducting sphere. Which picture best displays the arrangement of the surface charges on the sphere? While the charged rod remains in place, the sphere is grounded. Which picture now best displays the arrangement of the surface charges on the sphere? C C D D

8 charge Q lies directly below a charge +Q, while a third charge +q lies on the perpendicular bisector of the line joining +Q and Q. What is the direction of the force on q? +Q Q +q C D zero force

9 charge Q lies directly below a charge +Q. The point P lies on the perpendicular bisector of the line joining +Q and Q. What is the direction of the electric field at P? +Q Q P C D zero field

10 In the figure below, identical negative charges q are placed symmetrically around the origin on the x-axis and as a result the electric field at point P is directed upward along the y-axis. If a negative charge Q is now added at a point on the positive y-axis, what happens to the field at P? (ll of the charges are fixed in position.) y y Q q q x q q x P P. Nothing since Q is on the y-axis.. Strength will increase because Q is negative. C. Strength will decrease and direction may change because of the interactions between Q and the two q s. D. Cannot determine without knowing the forces exerted between particles.

11 Consider the electric field at the point marked due to two particles, each with charge q and separated by distance d in any of the four configurations shown below. Rank the configurations according to the magnitude of the electric field at, least to greatest. d #1 #2 q d q q d d q q d d #3 q #4 d d q d q. E 1 <E 2 <E 3 <E 4. E 2 <E 1 <E 3 <E 4 C. E 2 <E 1 <E 4 <E 3 D. E 2 <E 3 <E 4 <E 1

12 x 2 µc The figure shows the location and charge on four tiny conductors sitting in the xy plane. Consider the electric flux (Φ) through three gaussian spheres centered on the origin with radii as shown in the figure. Which of the below options best describes the relationship between the flux through these three spheres. (Φ 1 denotes the electric flux through sphere 1, etc.). Φ 1 > Φ 2 > Φ 3 1 µc 4 µc 1 µc y. Φ 1 < Φ 2 < Φ 3 1 C. Φ 1 = Φ 2 = Φ 3 2 D. Φ 2 < Φ 1 = Φ 3 3

13 The below figure shows, in cross section, three solid cylinders of differing radius (R) but identical material with charge density ρ. lso shown is the cross section of a Gaussian surface all three have the same radius (r) and length L. What is the magnitude of the electric field E anywhere on this Gaussian surface as a function of cylinder s radius R? Which of the below plots best displays the relationship between E and R? Gaussian surface r R solid, charged cylinder E E R R E C E D R R

14 The below figure shows, in cross section, three solid cylinders of differing radius (R) but identical material with charge density ρ. lso shown is the cross section of a Gaussian surface all three have the same radius (r) and length L. What is the magnitude of the electric field E anywhere on this Gaussian surface as a function of cylinder s radius R? Which of the below plots best displays the relationship between E and R? R r Gaussian surface E E solid, charged cylinder R R E C E D R R

15 The below figure shows, in cross section, three identical solid cylinders of radius (R) and with charge density ρ. lso shown is the cross section of three Gaussian surfaces; The three have the differing radius (r) but the same length L. What is the magnitude of the electric flux Φ through these Gaussian surfaces as a function of r? Which of the below plots best displays the relationship between Φ and r? R r Gaussian surface Φ Φ solid, charged cylinder r r Φ C Φ D r r

16 The below figure shows, in cross section, three identical solid cylinders of radius (R) and with charge density ρ. lso shown is the cross section of three Gaussian surfaces; The three have differing radius (r) but the same length L. What is the magnitude of the electric flux Φ through these Gaussian surfaces as a function of r? Which of the below plots best displays the relationship between Φ and r? r R Gaussian surface solid, charged cylinder Φ Φ r r Φ C Φ D r r

17 The below figure shows, in cross section, three identical solid cylinders of radius (R) and with charge density ρ. lso shown is the cross section of three Gaussian surfaces; The three have differing radius (r) but the same length L. What is the magnitude of the electric field E anywhere on these Gaussian surfaces as a function of r? Which of the below plots best displays the relationship between E and r? r R Gaussian surface solid, charged cylinder E E r r E C E D r r

18 infinite line charge Consider the case of an infinite, uniformly-charged wire sitting on the z axis. The electric flux through a disk of radius R, sitting in the xy plane and centered on the origin is: R. 2 π R E. + π R 2 E C. π R 2 E D. 0

19 10 V 20 V 30 V 40 V 50 V 10 V 20 V 30 V 40 V 50 V 10 V 20 V 30 V 40 V 50 V I III II.The smallest work is required in I.. The largest work is required in II. C. The largest work is required in III. D. ll three would require the same amount of work. The above shows the location of equipotential lines (displayed as the dotted lines with corresponding voltages). In each case, an object with charge +1µC is moved from to. In this problem we consider the work required to make these moves.

20 10 V 20 V 30 V I 40 V 10 V 50 V 20 V 30 V 40 V 10 V 20 V 50 V 30 V II 40 V 50 V. E III > E II > E I. E I > E III > E II C. E II > E I > E III III D. E I = E II > E III The above shows the location of equipotential lines (displayed as the dotted lines with corresponding voltages). In this problem we consider the magnitude of the electric field at the point in the three cases.

21 Q Q +Q +Q Consider four charges all of equal magnitude, but two are positive and two are negative. They are arranged as shown in a square. The voltage at the center of the square (marked with X) is:. zero. points up C. points right D. point to the left

22 Q V C Plots of charge Q vs. potential difference V for three different capacitors are displayed below along with the area and plate separation of these three capacitors. Which plot goes with which capacitor? area plate separation 1 d 2 2 d 3 2d

23 reduce plate separation parallel-plate capacitor is connected to a battery of electric potential difference V. If the plate separation is then decreased do these quantities: : increase : decrease C: stay the same 1. capacitance 2. potential difference between plates 3. charge on a plate 4. energy stored 5. electric field between plates 6. energy density between plates V

24 square (side s) parallel-plate capacitor carries a charge Q, but is otherwise isolated (disconnected). If the plate size s is increased (with other parameters unchanged) do these quantities: : increase : decrease C: stay the same 1. capacitance 2. electric field between plates 3. potential difference between plates 4. energy stored 5. energy density between plates s +Q Q d

25 parallel-plate capacitor carries a charge Q, but is otherwise isolated (disconnected). If the charge Q is then increased do these quantities: : increase : decrease C: stay the same 1. capacitance 2. potential difference between plates 3. electric field between plates 4. energy stored 5. energy density between plates +Q Q

26 resistor consists of a long cylinder of carbon (radius a, length l) and carries a current I. If the current I is then increased do these quantities: : increase : decrease C: stay the same I 1. resistance 2. potential difference 3. electric field 4. resistivity 5. power 6. current density 7. drift velocity l 2a

27 resistor consists of a long cylinder of carbon (radius a, length l) and carries a current I. If the radius a is then increased do these quantities: : increase : decrease C: stay the same I 1. resistance 2. potential difference 3. electric field 4. resistivity 5. power 6. current density 7. drift velocity l 2a

28 V +Q Q Dielectric κ n isolated parallel plate capacitor holds a charge Q. dielectric slab (dielectric constant κ > 1) can exactly fit between the plates. If the dielectric is inserted. the charge on the plates and the voltage will increase.. the capacitance will increase and the voltage will decrease. C. the electric field between the plates will increase. D. the capacitance and the electric field between the plates will decrease.

29 2 µf capacitor (C 1 ) and a 4 µf capacitor (C 2 ) are connected in series and I attach a 6 V battery between points a and c a 2 µf 4 µf b C 1 C 2 How does the charge Q 1 stored on C 1 compare to the charge Q 2 stored on C 2? c. Q 1 < Q 2. Q 1 > Q 2 C. Q 1 = Q 2 How does the voltage drop across C 1 : V(ab) compare to the voltage drop across C 2 : V(bc)?. V(ab)=2 V(bc). 2 V(ab)= V(bc) C. V(ab)= V(bc) D. None of the above

30 2 µf 2 µf capacitor (C 1 ) and a 4 µf capacitor (C 2 ) are connected in parallel and I attach a 6 V battery between points a and b e c a C 1 C 2 4 µf f d b How do the voltages at a, c, and e compare?. V a < V c < V e. V a > V c > V e C. V a = V c = V e D. None of the above How does the voltage drop across C 1 : V(ef) compare to the voltage drop across C 2 : V(cd)?. V(cd)=2 V(ef) C. V(cd)= V(ef). 2 V(cd)= V(ef) D. None of the above

31 2 µf 2 µf capacitor (C 1 ) and a 4 µf capacitor (C 2 ) are connected in parallel and I attach a 6 V battery between points a and b e c a C 1 C 2 4 µf f d b How does the charge Q 1 stored on C 1 compare to the charge Q 2 stored on C 2?. 2Q 1 = Q. C. 2 Q 1 = 2Q 2 Q 1 = Q 2 D. None of the above

32 V V 1.5 V battery V C 1. V? 1.5 V battery V Z V D 2. V? 3. V C? 4. V D? V Z is defined to be 0 Volts : 3 V : 1.5 V C: 0 V D: none of the above

33 1.5 V battery 1.5 V battery V V V C 1. V? 2. V? V Z V D 3. V C? 4. V D? V Z is defined to be 0 Volts : 3 V : 1.5 V C: 0 V D: none of the above

34 1. Which bulb has the greater resistance? 2. Which bulb will shine brighter. 25 W. 40 W C. Same

35 #1 #2 #3 Identical batteries power identical light bulbs in the three circuits. Which circuit produces the most total light?. Circuit #1. Circuit #2 C. Circuit #3 D. #1 and #2 produce the same total light

36 #1 #2 25 W 40 W 25 W 40 W Which bulb is brighter?. 25 W. 40 W C. Equally bright 25 W 40 W #3

37 Which bulb will shine the brightest? D C D C

38 15 Ω 30 Ω 30 Ω With the switch as shown (open) the ammeter reads 1. When the switch is closed, the current:. increases slightly. decreases slightly C. remains the same D. doubles R 1 R 1 > R 2 > R 3 Rank the current in the resistors. R 3 R 2. I 1 > I 2 > I 3. I 1 < I 2 < I 3 C. I 1 = I 2 = I 3 D. none of the above

39 10 kω 100 pf 10 V 100 µα 1 m 1 µs 1 µs 1 mα C 1 m D 10 ms 1 µs

40 100 kω 0.1 µf 10 V 100 µα 1 m 1 µs 10 ms 100 µα C 1 m D 10 ms 1 µs