94.20: A magnet is dropped through a vertical copper pipe slightly larq;66o .acjhcovqku52 ger than the magnet. Relative to the speed it woul q.c 2uc6jk o5ah6v;oqd fall in air, the magnet in the pipe falls:

  01.30: Lenz's law concerning the dtq..p 4)y+wzc 8.zleuj wx.d rirection of an induced current in a conductor by a magnyd. wcxqz..jtlp w )ru.+84zeetic field could be a restatement of

  11.25: The product (3 Tesla0q r7(p 97y5ay*w)kmbb3xvi mkm;g8+ fx nm vjs) × (2 meters) × (4 meters/second) is equivalent to whic *9qbwy53+py(a8xxmn7vb m mgrfm0j7i )vk;kh one of the following?

  04.34: A square loop is placed in a uniform magnevsj8/ af m:o2d/hz*aytic field perpendicular to the plane of the loop as shown. The loop is 0/m*fa/ 8:sz 2hydojva.5 meters on a side and the magnetic field B has a strength of 2 T. If the loop is rotated through an angle of $90^{\circ}$ in 0.1 second what would be the average (RMS) induced EMF in the loop?

  97.32: A wire moves through a magnetic field directed intoz*,3qa 2,:)v)novc. dmmx qic 1gkazw the page. The wire experiences an induced charge separa cvg21cm z vxn,q):wzk*.,) a3mo iqdation as shown. Which way is the wire moving?

  00.20: A wire moves with a gw,7 j : kji ogf..s3n1ke+vcuvelocity v through a magnetic field and experiences an induced charge separation as shown. What is the direction of the magnetic s kogvfwgu j .,+n31k7ej.ic :field?

  05.33: The figure below shows a bar mo pj*z/:jc -9b h2cah/oz kkmj2ving to the right on two conducting rails. To make an induced current i in the direction indicated, in what direction would the magnetic field be in the area contained within th:pzjajhco22/zkhmj/ 9 k -b*ce conducting rails?

  00.10: When a wire moving through a magnetic field 47pvq-n u9 un+cp9n yihas a voltage induced between the wire’s ends, that voltc yqvi49u-pu pnn 97+nage is
I. directly proportional to the strength of the magnetic field
II. directly proportional to the velocity of the wire
III. directly proportional to the diameter of the wire

  95.30: A 0.20 m long copper rod h,ev6 ab 8ve8ghas constant velocity 0.30 m/s traveling through a uniform magnetic field of 0.060 T. The rod, velocity, and magnetic field ar 6,vg vea8be8he all mutually perpendicular. What is the potential difference induced across the rod’s length?

  04.42: A solenoid is oriented end-on so that its opening is perpcbjm( c:bv(j/ 7zlzm)endicular to the circuit containing the two livjl c( zjb/mc(7:b )zmght bulbs as drawn in figure C1. For figures C2 and C3, a shorting wire of negligible resistance is added as shown. Assume that the magnetic field from the solenoid, shown coming out of the plane of the page, decreases uniformly in time at the same rate for each circuit. Rank the circuits for the brightness of the bulb labeled R1 from brightest to dimmest.

  07.34 For the solenoids shown in the diagram (which are assumed to b8 tqsb -8v5uveslip(a 6:u6dqe close to each other), the resistance of the left-hand circuit is slowly inc 8l qepbi5 8(v-6suuqvds:6t areased. In which direction does the galvanometer needle in the right-hand circuit move in response to this change?

  08.29: A strong bar magnet is held very close to the 9 yl sgn62zkj6opening of a solenoid as shown in the diagram. As the magnet is moved away from the solenoid at constant speed, what is the direction of conventional current through the resistor shown and what is the direction of the force on the magnet because of the induced c jnsl266k9zy gurrent?

  09.37: For the figure shown, the variable resistance in the circuit on the left c ryy8bd xm00l*d+: ckis increased at a constant rate. What is the direction of the magnetic field at the point P at the center of the left-hand circuit andb+0 c dy8dc:rlk0* xmy in what direction is the conventional current through the resistor in the right-hand circuit?

  10.39: A strong bar magnet is held very close to tw)nk)l g;f: plhe opening of a solenoid as shown in the diagram. As the magnet is moved to the left toward the solenoid, a conventional current through the resistor shown is directed from A to B. What is the direction of the force on the bar magnet because of the induced current in the solenoid and which magnetic pole does the “??” in the diaglpfg nkl;w)):ram represent?

  14.34: Two circular loops of resistive wire aisf2/l0 p tz4oi.k al6re placed next to each other as in the figure. The circular loop on the left is connected to a constant voltage source V. The resistance of this loop is increasing linearly with tiat ioz.620/k4sl lpfime. As the resistance is changing, what is the direction of the magnetic field at point P (the center of the left-hand loop) and what is the orientation of the conventional current in the right-hand loop (as viewed in the figure from above)?

  11.41: For the figure shown, the variable r/rdlh ucxc 5tinx;f1 93722hf dqhm y*esistance of the outer circuit $R_{inner}$ is decreasing at a constant rate. While this is occurring, in which direction is the magnetic field associated with the outer circuit at the point P in the plane of the circuit and in which direction is the conventional current through the resistor $R_{outer}$ in the smaller interior circuit? The two circuits lie on a flat table.

  13.35: For the figure shown, the variable resistance of the innercirckz 4dj+0woueed,4z ..8qqvy 9ow *f nwuit $R_{inner}$ is increasing at a constant rate. While this isoccurring, in which direction is the magnetic field associated with the inner circuit at the point P in the plane of the circuitand in which direction is the flow of electrons through the resistor labeled $R_{outer}$?

  12.38: A square, conduckzl6u4 tpzpu .1pcpel/t , e;5ting wire loop sits in a plane perpendicular to a spatially uniform magnetic field pointing into the plane z;l e.t zkue5cp64ppp/l,t1 uof the page as shown. The magnetic field strength steadily increases with time. Which one of the following effects best describes the result of this field increase?

  16.47: Two small loops of wire are located close to a wire with6wv1gym 8unzc:3 l9va conventional current directed up the page. A scientist then moves the loops away fra :8yvw1znmg39ucv l6om the current as shown. What is the orientation of the conventional current in each loop while this occurs?

  17.35: A metal bar is moving to th;k:tat h0cjk* e left across a set of frictionless conducting rails as seen in the figure. Throughout the region between the rails, there is a uniform magnetic field directed into the plane of the page. The resistors labeled X and Y are identical. Which one of the following choices correcatt j;: kh*k0ctly indicates the direction of the conventional current in the resistors and the relation between the magnitude of the currents through each resistor at the instant shown?

  08.50:. An infinitely long solenoid passes through the circuit as s75 +o yglvctbgdao-3+hown. The magnetic field of the sotba +o odv 3g-5+cylg7lenoid, directed into the
plane of the page, is weakening which produces a constant emf of magnitude ξ for a closed loop around the outside of the solenoid. Once equilibrium is established in this circuit, what is the voltage across the switch S?

  15.50 A magnetic field directed into the plane of the page is decreasing in q)/ hdwad6lwkxhu 7k9r01 t.s time. A constant emf ξ is produced for the square loop enclosing the field in the figure. Th .klh kd1tr/7)awuq0 6wdx9she square loop has three identical light bulbs of resistance R in it and an ideal voltmeter connected to the corners through the center of the loop. What is the magnitude of the voltmeter’s reading?