Exam II review.RII-1 How many ohms in a coulomb?A) one gazillion B) one coullion C) 17D) None of theseRII-2 Consider a positive point charge +Q just outside an imaginary sphere, as shown. How does the magnitude of the electric flux thru the left half of the sphere LeftE da��vvcompare to the magnitude of the electric flux thru the right halfRightE da��vv:A) |Flux Left| > |Flux Right|B) |Flux Left| < |Flux Right|C) |Flux Left| = |Flux Right|+QRII-3 Consider a point charge +Q off-center within a spherical metal shell. Does Gauss's Law allowyou to compute the total charge on theinside surface of the shell? A: Yes B: NoRII-4 A point charge +q is brought from infinity to a point b near 3 other charges +Q,–Q, and +2Q. The charge q is brought along 3 different paths in turn, path 1, path 2, and path 3, as shown. Along which path is the most work done by the external agent carrying the charge +q?A) 1 B) 2 C) 3 D) Same work on all three paths+2Q–Q+Q bpath 1path 2path 3+QRII-5 TRUE (A) or FALSE (B) ?If the E-field throughout a region of space is zero, the voltage throughout that region must be zero.RII-6 TRUE (A) or FALSE (B) ?If the voltage throughout a region of space is zero, the E-field throughout that region must be zero.RII-7Does the capacitance of a capacitor depend on the charge Q on the capacitor?A) Yes B) No C) Depends on the type of capacitor.RII-8A capacitor is attached to a battery which maintains a constant voltage V across the capacitor plates. While the batteryis attached, the plates are moved further apart. The energy stored in the capacitor..A) increased.B) decreased.C) remained constant.Hint: U = (1/2)QV = (1/2)Q2/C = (1/2) CV2 VRII-9 A charged capacitor is isolated (so no charge can get on or off). The plates of the capacitor are slowly pulled apart. After the plates are pulled apart a bit, the electric field between the plates A) increased B) decreased C) remained constantThe voltage difference between the plates..A) increased B) decreased C) remained constantThe capacitance ..A) increased B) decreased C) remained constantRII-10A copper wire and an aluminum wire both have the same dimensions (same length, same cross-sectional area). Which one statement is true?A) Both wires have the same resistance R and the same resistivity .B) The wires have different R and different .C) The wires have the same R but different .D) The wires have different but the same R.RII-11 Which has higher resistance ? A) 100 W bulb B) 60 W bulb C) Same R in both.Hint: P = IV = I2R = V2/RRII-12The voltage between points a and b in the circuit shown ismeasured with an ideal voltmeter. What does the voltmeter read?Hint: Recall that an idealvoltmeter has infinite internalresistance.A) V/2 B) V/3C) V/4 D) zero E) VV R a b R RRII-13 Consider the circuit below. What is the total resistance which the battery sees?A) 1 B) 2 C) 0.5 D) 0.25 In the circuit above, the resistor R2 is increased to 5. What happens to the current through from the battery?A) increases B) decreases C) remains constant R2 =2 1 R1 =2 2 1V I=?RII-14 In the circuit below which resistors must have the same current flowing through them? Do not assume that the resistors are identical.A) R2 / R5 onlyB) R3/R4 onlyC) R2 / R5 and R3/R4 onlyD) R1/ R2 / R5 onlyWhich resistors have the same voltage drop?A) R2 / R5 onlyB) R3/R4 onlyC) R2 / R5 and R3/R4 onlyD) R1/ R2 / R5 onlyR4 R2 R1 R3 1V R5RII-15 How many following statements is/are true aboutthe following circuits? Assume all batteries and all bulbsare identical.I) Bulb A does not turn on, because the voltage differenceacross it is zero.II) Bulb B does not turn on, because the voltage differenceacross it is zero.III) Bulb C does not turn on, because the current flowingthrough it is zero.Answer: All three are true: (I) is true, (II) is true, (III) istrueRII-16 What is the correct order for the total powerdissipated in the following circuits, from least togreatest? Assume all bulbs and all batteries areidentical. Ignore any internal resistance of the batteries.a)A < B = C < D < Eb)D < C < B = E < Ac) D < B < E < A < Cd)A = B < D < C < Ee)B < A < C = D < EAnswer: Assume that all bulbs have same resistance R and all batteries have same voltage V. The total resistances are A) 3R, B) R (since 2 of the R are shorted by the wire), C) R, D) R / 3 , E) R.The total voltages are A) V, B) V, C) V (since batteries in parallel), D) V, E) 2V (since batteries in series).The total power is Ptot = Vtot2 / Rtot A) P = V2 / (3R), B) V2 / R , C) V2 / R , D) V2 / (R / 3) , E) (2V)2 / RSo A < B = C < D <
View Full Document
Unlocking...