TIME OF COMPLETION_______________ &nb= sp; NAME__SOLUTION________= ___________________

<= span style=3D'font-family:"Times New Roman","serif"'> &nbs= p; &= nbsp; &nbs= p; DEPARTMENT OF NATURAL SCIENCES

PHYS 1112, Exam 3 &= nbsp; &nbs= p; &= nbsp; &nbs= p; &= nbsp; &nbs= p; &= nbsp; &nbs= p; Secti= on 1

Version 1 = &nb= sp; = &nb= sp; = &nb= sp; = &nb= sp; = April 27, 2011

Total Weight: 100 points

1. = Check your examination for completeness prior to starting. There are a total of nine (9) prob= lems on six (6) pages.

2. = Authorized references include your calculator with calculator handbook, and the Refere= nce Data Pamphlet (provided by your instructor).

3. = You will have 50 minutes to complete the examination.

4. = The total weight of the examination is 100 points.

5. = There are six (6) multiple choice and three (3) calculation problems. Work all ca= lculation problems and 5 (five) multiple choice.&nbs= p; Show all work; partial credit will be given for correct work shown.<= o:p>

6. = If you have any questions during the examination, see your instructor who will=

be located in the classroom.<= o:p>

7. = Start: &= nbsp; 2:00 p.m.

Stop: = 2:50 p.m.

<= /p>

&nbs= p; PROBLEM

<= /p>

&nbs= p; POINTS

<= /p>

&nbs= p; CREDIT

<= /p>

&n= bsp; = ; 1-6

<= /p>

&n= bsp; = ; 25

<= /p>

&n= bsp; = ; 7

<= /p>

&n= bsp; = ; 25

<= /p>

&n= bsp; = ; 25

<= /p>

&n= bsp; = ; 9

<= /p>

&n= bsp; = ; 25

<= /p>

&nbs= p; TOTAL

<= /p>

&nbs= p; 100

<= /p>

PERCENTA= GE

<= /p>

CIRCLE THE SINGLE BEST ANSWER FOR ALL MULTIPLE CHOICE QUESTIONS. IN MULTIPLE CHOICE QUESTIONS WHICH REQUIRE A CALCULATION SHOW WORK FOR PARTIAL CREDIT.

1. A proton in a magnetic field does n= ot experience a force. Which of the following statements is correct with respe= ct to the situation?

&n= bsp; I. The proton may have a velocity of zero m/s.

&n= bsp; II. The proton may be moving parallel to the direction of the magnetic field.

&n= bsp;

&n= bsp; (A) Statement I only.

&n= bsp; (B) Statement II only.

(5) &= nbsp; (C) Neither statement I nor statement II.

&n= bsp; (D) Both statement I and statement II. <= /span>

2. A resistor, a capacitor, an= d an inductor are connected in series across an AC source. Which of the following statements is false? (Select all that apply.)

(A)1

The instantaneous voltage across the capacitor l= ags the current by 90°. =

(B)The instantaneous voltage across the inductor leads the current by 90°.

&= nbsp; (5)

(C)The instantaneous voltage across the resistor is in phase with the current.

(D)The voltages across the resistor, capacitor, and inductor are not in phase.

(E)The rms volta= ge across the combination of the three elements equals the algebraic sum of th= e rms volta= ges across each element separately.

3. A rectangular conducting loop is placed near a long wire carrying a current <= i>I as shown in the figure below. If I decreases in time, what can be said of the current induced in the loop?

3D"http://www.webassign.net/serpse8/31-oq-003.gif"

<= /o:p>

(A)1

The direction of the current depends on the size= of the loop. <= o:p>

(B)The current is clockwise

(5)

(C)The current is counterclockwise

(D)The current is zero=

(E)Nothing can be said abou= t the current in the loop without more information.

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4. The bar shown in the figure= below moves on rails to the right with a velocity 3Dvarrow= , and a uniform, constant magnetic field is directed out of the page. Which of the following statements are correct?

= ; 3D"http://www.webassign.net/serpse8/31-oq-006.gif"

5.1

(A)The induced current in t= he loop is zero.

(B)The induced cu= rrent in the loop is clockwise.

(5)

(C)The induced current in t= he loop is counterclockwise.

(D) The induced current in = the loop is to the left.

(E) No force is required to= keep the bar moving at constant speed.

5. Three particles travel through a r= egion of space where the magnetic field is out of the page, as shown below. The electric charge of each of the three particles is, respectively,

&nbs= p; &= nbsp; &nbs= p; (A) 1 is neutral, 2 is negative, and 3 is positive.<= /span>

<= o:p>

&nbs= p; &= nbsp; &nbs= p; (B) 1 is neutral, 2 is positive, and 3 is negative.<= /span>

&nbs= p; (5)

&nbs= p; &= nbsp; &nbs= p; (C) 1 is positive, 2 is neutral, and 3 is negative.<= /span>

&nbs= p; &= nbsp; &nbs= p; (D)1 is neg= ative, 2 is neutral, and 3 is positive.

&nb= sp;

&nbs= p; &= nbsp; &nbs= p; (E) It is impossible to find based on the given information.<= /p>

3Dsummer=

6. At a particular instant, a proton moves eastward at sp= eed V in a uniform magnetic field that= is directed straight downward. T= he magnetic force that acts on it is

&nbs= p; (A) Zero. <= /span>

&nbs= p; (B) Directed upward. <= o:p>

(5)

&nbs= p; (C) Directed to the north. =

&nbs= p; (D) Directed to the south.

&nbs= p; (E) Directed downward.=

&= nbsp; &nbs= p;

= 7. A solenoid of radius 2.70 cm has 370 turns and a length of 21.0 cm.

(a) Find its inductance.

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8. A horizontal power line of = length 62.7 m carries a current of 2.08 kA northward as shown in the figure below.= The Earth's magnetic field at this location has a magnitude of 5.40 3D"http://www.webassign.net/images/multiply.gif" 10^-5 T. The fiel= d at this location is directed toward the north at an angle 65° below the po= wer line.

3D"http://www.webassign.net/serpse8/29-p-039.gif"

(a) Find the magnitude of the magnetic force on the power line.

(b) Find the direction of the magnetic force on the power line.

out of the page into the page counterclockwise clockwise=

9. An RLC circuit consists of a= 130 3D"http://www.webassign.net/images/omegacap.gif" resistor, a 21.0 µF capacitor= , and a 400 mH inductor, connected in series with a 1= 20 V, 60.0 Hz power supply.

(a)What is the impedance of= the circuit?

(b) Find the rms current in the inductor= .

(d) Find the phase angle.

(e) Does the current lead t= he voltage in this circuit, or lag behind?

Current lags behind since the phase angle is pos= itive. &= nbsp; &nbs= p; &= nbsp; &nbs= p; &= nbsp; &nbs= p; &= nbsp; &nbs= p; &= nbsp;