94.20: A magnet is dropped through a vertical copper pipfb5y2upz0 89n hk m izv)4wf9 2qji7lre slightly larger than the magnet. Relative to the speed it would fall in aiyn)4u07zf2kiz lqm59r 2vpfh 8 9wjibr, the magnet in the pipe falls:

  01.30: Lenz's law concerning the direction of ank)(s2 qgbk;yfc m jt9; induced current in a conductor byqcbky()fj 2 ms g9t;k; a magnetic field could be a restatement of

  11.25: The product (3 Teslas) × (2 meters) × bgkw(vjd,04 md;bg9z (4 meters/second) is equivalent to which one of the followidd g049bb,;mg jv(w zkng?

  04.34: A square loop is placew-gu ; (jumm,7cnc (qzd in a uniform magnetic field perpendicular to the plane of the loop as shown. The loop is 0.5 meters on a side and the magneticcuu m(cjnzw;g- ( 7m,q 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 intw -zw0j 6o)*xz xtfusei0v*x0z6(z wvo the page. The wire experiences an induced charge separat iw-of6v zwxt0 6jsz(0*wux) 0zv*xzeion as shown. Which way is the wire moving?

  00.20: A wire moves with a velocity v through;yt/- 3zqylify30 n tx a magnetic field and experiences an3 30 - ;qxftn/yylizty induced charge separation as shown. What is the direction of the magnetic field?

  05.33: The figure below showus5z ,ex,un 7 fnr3/dbs a bar moving to the right on two conducting rails. To make an induced current i in the direction 3/nuxz ub5sn7fe ,dr, indicated, in what direction would the magnetic field be in the area contained within the conducting rails?

  00.10: When a wire moving through a +e(mr*bb4dy+wc/g6ixz rto + magnetic field has a voltage induced between the wire’/ yb+ eb*xw4+(d o 6rz+ctgirms ends, that voltage 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 has constan8. t2jsx4xr5do4i wiu sak7x/ t velocity 0.30 m/s traveling through a uniform magnetic field of 0.060 T. The rod, velocity, and magnetic s w2i5 atk7x i4rxoxud/j.s48field are all mutually perpendicular. What is the potential difference induced across the rod’s length?

  04.42: A solenoid is oriented end-on so thatx - 0xel + hfv666b,q anw8ks+hxanon; its opening is perpendicular to the circuit containing the two light bulbs as drawn in figure C1. For figures C2 andfnh 6kha-xlqa+6xw80ve,;n nb o +x6s 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 be close to 6c,w9m 9s:t4tv hc4lop-uodw each other), the resistance of the left-hand circuit is slowly increased. In which direction does the galvanometer needle in the ri-od :mtcuph9c 4 ,964 vtlwowsght-hand circuit move in response to this change?

  08.29: A strong bar magnet is f b:cpybp9u ( p g(:5whocq;7:gq1ofte4 w0ia held very close to the opening of a solenoid as shown in the diagram. As the magnet is moved away from the solenoid at constant speed, what isy(qeuw0 5tpg79pfi (;wpb1:acb ohg:c4 f qo: the direction of conventional current through the resistor shown and what is the direction of the force on the magnet because of the induced current?

  09.37: For the figure shown, the variable ycgb:bv0/ sl1t4: 4jd6xbog2af cer/ resistance in the circuit on the left is increased at a constant rate. What is the direction of the magnet:bl s/b2gr4061xj4fdce o:a bvgtyc /ic field at the point P at the center of the left-hand circuit and 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 the opening r-s9gp sw9tvhlod/0;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 magneg-s lt/9 po;rhs vwd90t because of the induced current in the solenoid and which magnetic pole does the “??” in the diagram represent?

  14.34: Two circular loops of resistive wire are placed next t ls l ./v c25lwai2qm 6xmlhld8j9dl;,o 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 time. As the resistance is changing, whash562,mlm l2/vlwiadlj9d; cx 8l .lq t 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 resistance of :2:bp a1j9svz qbax4psd9sl 5the 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, thf35 l.jknp ;exe variable resistance of the innercircuit $R_{inner}$ 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, conducting wire loop sits inpgr)9)0;vj o .h oqfsa a plane perpendicular to a spatially uniform magnetic field pointing into the plane of 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 increar pq0s)h9)vof ao.j; gse?

  16.47: Two small loops of wire are located close to a wire with conven*d9qo ucs u xsiog698c,q5 /jrtional current directed up the page. A scientist then moves the 58coou q s9,i*6 us9j/qgr xcd loops away from 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 the left across a set of lxzp-npk6oqo , i8h)7 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 t pz8oi)pqk ,ho7ln x6-he page. The resistors labeled X and Y are identical. Which one of the following choices correctly 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 circt. b d5llo6olkz ;/3fvuit as shown. The magnetic field ;z5blod .3 /f6 voktllof the solenoid, 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 decrelp 6a0inr ywi4*hbx+mi5 ,nk, asing in time. A constant emf ξ is produced for the square loop enclosing the field in the figure. The square loop has three idx,+lii4b6hm,pnar*w0y k5 n i entical 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?