94.20: A magnet is dropped through a verd lg m 7227htfi)srwj4tical copper pipe slightly larger than the magnet. Relative to the speed it would fall in air, the magnet in thi djl7srht 7mg2)2w4fe pipe falls:

  01.30: Lenz's law concerning the direction of an induced curre4 qj 3nad,m;rent in a conductor by a magnetic field coula4djqrmn;e ,3 d be a restatement of

  11.25: The product (3 Teslas) × (2 meters) × (4 meters/second) is equivalent, qx8j7q*cen 6hkm-b hx1+fqy to which one of the following?h1*qqn c6-xq m87bx+jhf ke, y

  04.34: A square loop is placed in a uniform magnetic field perpendicular to t-ohx kype//(r1vy2 mdhe plane of the loop as shown. The loop is 0.5 meters on a side and the magnetic fieldxp/mrk/2- ohvydy 1e( 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 th b75hx7n: c qqz6zt l)la(bx0grough a magnetic field directed into the page. The wire experiences an induced charge separation as shown. Which wayl xn b7tcq0(xl5b 6zaq :7hzg) is the wire moving?

  00.20: A wire moves with a velocity v through a magnetic f g+v(h2vp 6g( 0z9ratzdu dv+oield and experiences an induced charge separation as shown. What is the direction of thed(+29g hvvo ap (vuz0rd6+tzg magnetic field?

  05.33: The figure below shows a bar moving to the riuei38scc3m 0zur1lc2b( d,ud11qrhw ght on two conducting rails. To make an induced current i in the direction indicated,bwd1d3 qm z8sr c1hu c2 reiu10,(lcu3 in what direction would the magnetic field be in the area contained within the conducting rails?

  00.10: When a wire moving through a magnetic field ha* a 7f1amgbv,4ifp au,s a voltage induced between the wire’*,a1ifbgf7va pa , 4mus 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 hasmohb7(.sz 16 c;2p p,yuxfmls constant velocity 0.30 m/s traveling through a uniform magnetic field of 0.060 T. The rod, velocity, and magnetic field are all mutually perpendicular. What is the potlz;pf,6 sp hm(yoxb.u1cs m 72ential difference induced across the rod’s length?

  04.42: A solenoid is oriented end-ox lk5zkyu l7pwq hg,//wy 5d39n so that its opening is perpendicular to the circuit cop/3kyuk9 qg,zx l wl5d yw/h75ntaining the two light 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 aq 1 zw bp6fj/eg6ae.d7re assumed to be close to each other), the resistance of the left-hand circuit is slowly ij71 d/eq6p bzwgf.6eancreased. 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 opening oezsb)q jf+x + ni5a0xu vrx)aq5; a/7df a solenoid as shown in the diagram. As the magnet is moved away from the solenoid at constant speed, what is tx)aq0rqa)xsex uv5d af b;nzj+57i /+he 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 resistance in the circui;8i zhpbnru4tml e(jj97zh( 2t on the left is increased at a constantz;982 zmu (e7pj( nl hibht4rj rate. What is the direction of the magnetic 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 closvz7)6n mstu+p e to the 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 polsn7t+z )u mpv6e does the “??” in the diagram represent?

  14.34: Two circular loops of resistive wire are placed next to eachqij 9lsjr kr90:xt3j/ 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, what is the direction of the magneticrj r3q/lsi jtx:9k90j 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 resistan l/hnxcz/c u o+0o28moce 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 thpngqc 846h orxx-tvoj5vd1-: e 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 siterr9,xa+z7vkhgmcwpw d 5af5;kz .0) s in a plane perpendicular to a spatially m ecw 9dzk +7wk afz5g5rv,)0xrpha;.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 increase?

  16.47: Two small loops of wireu7:uy 1ucy d:a are located close to a wire with conventional current directed up the page. A scientist then moves the loops away from the current as shown. What is the orientation of :7ud yacu: yu1the conventional current in each loop while this occurs?

  17.35: A metal bar is moving to the left1lb 2-,w5*xr7dm.c aayamvud 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 correctly indicates the direction of the conventi ca*dw m7 b1mu,vy.2aa x5dr-lonal current in the resistors and the relation between the magnitude of the currents through each resistor at the instant shown?

  08.50:. An infinitely lo/6jh-v tyzo tm 3f1so6l*bsj.ng solenoid passes through the circuit as shown. The magnetic field of the soleno6of 1zy*tl6so.t/hmv- jjbs3id, 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 oox tvt )ps:t--f the page is decreasing in time. A constant emf ξ is produced for the square loop enclosing the field in the figure. The 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 th-ot)t:s xtpv -e magnitude of the voltmeter’s reading?