94.20: A magnet is dropped through a vertical copper pipe slightly larger thanr14zf )yv8g/pdtyff0 yajv 8*3 v, afa the magnet. Relative to 8 gd)* 8vvyra p0av yfy/f 4j1f3a,tfzthe speed it would fall in air, the magnet in the pipe falls:

  01.30: Lenz's law conlvs-fbok 9177dkpk13h m*qy bcerning the direction of an induced current in a conductor by a magnetic field could be a rev 9fqosby d7hlbm-11 kk37* pkstatement of

  11.25: The product (3 Teslas) × (2 meters) × (4 meters/se8 pwuy15s6ddk9 vtr:trv4 h(i:-zxdp cond) is equivalent to whi4d:ptr :vr xd 9(6yhz it 5-kpswud81vch one of the following?

  04.34: A square loop is placed in a uniform magnetic field perpendicular to j(tl-ug*7.j cu p lr;pthe plane of the loop as shown. The loop is 0.5 meters on a side and the magnetic field B has a strength of 2 T. If the loop is rol (*pjgutl . j;p-cr7utated 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 into the page. Ta .sur8:c idy;yx xh+2he wire experiences an induced charge separation as shown. Which way is the wire movas.+x :y;8dih y2 xrucing?

  00.20: A wire moves withtl/o : gzy-y p5o+j9yh ;qp1oa a velocity v through a magnetic field and experiences an induced charge separa q/: ;yytyo5h-p+9zaj1op glotion as shown. What is the direction of the magnetic field?

  05.33: The figure below shows a bar moving to the right on two conducting rakgba1qd h 6y:2(cwt7cils. To make an induced current i in the direction indicha d6twqcgbk(7 1y2:cated, 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 fi;9hpz n(xt jz9eld has a voltage induced between tp n9zj h9tzx;(he wire’s 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 ha:fu5 jbry6k43fd oay1 s constant velocity 0.30 m/s traveling through a uniform magnetic field of 0.060 T. The rod, velocity, and ma a5yu6k:1fj34b fr dyognetic field are all mutually perpendicular. What is the potential difference induced across the rod’s length?

  04.42: A solenoid is orm. vw5xwk5lz(9fj g3giented end-on so that its opening is perpendicular to the circuit containing 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. Rankk9g.g(5m5jwvxzf3 wl the circuits for the brightness of the bulb labeled R1 from brightest to dimmest.

  07.34 For the soleno6e8)w9a. wu-wx oedeu ids shown in the diagram (which are assumed to be close to each other), the resistance of the left-hand circuit is slowly increased. In which direction does the galvanometer needle in the right-hand circuit move d w-9e8x6)w.u ea oeuwin response to this change?

  08.29: A strong bar magnet is held very close to the opening of a soleno(o):9gxo( j e6xppc0a 5.g.tia qjmulid as shown in the diagram. As the magnet is moved away from the solenoid at constant speed, what is the p(ju9 5ip g:c(o.)tml ae 6 xaxq0gj.odirection 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 showjarbb- 8, zs k)() i6av9jbwown, the variable resistance in the circuit on the left is 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 s 8w6az(kw, o)rvj bb)aj9-b iand in what direction is the conventional current through the resistor in the right-hand circuit?

  10.39: A strong bar magneu5 n ksul)byexc p6d0i-l:3b; t is held very close 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 resin;ic3p 6bx:-5ksl yu)0 dbluestor 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 diagram represent?

  14.34: Two circular loop+h ex:cr88*shm .vn nas of resistive wire are 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 time. As tha:88h.* nrsxvcnme + he 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, t2fr*; fdv ;q7gghq y*w qnbu9:he variable resistance 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 resistao5 4p sr+dfu(gmb9e5mnce 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 in 7o ; stwblrnbail8267a plane perpendicular to a spatially uniform magnetic field po2ll;bwt b8o6 7s7ani rinting 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 wire are located close to a wir sowd8h:25 iohfb+px, *kr- spe with conventional current directed up the page. A scientist then moves the loops away from the current as shown. What is the orientation of the conventional current in each loop while th 8h*b ,ss -x2dwoi+koppf:5rhis occurs?

  17.35: A metal bar is moving to the left across a set of frictionless gc*lce*a ruqn,-rdrre -534z 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 folloc34 -5grc nd raz- re,qeul*r*wing 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 soleno rjox5v1/f c*9h9a;jiu 9cp b2qoay41 9re oacid passes through the circuit as shown. The magnetic field of the solevcu/a91hxopc9 fe2 biaojc4a9*oq9 r;1 jry5 noid, 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 6;ljm,hm9 +(vzrl,q 7 kktckzis 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 voltm;+ 7jz9hk lkz(m krq,vlc,6tmeter connected to the corners through the center of the loop. What is the magnitude of the voltmeter’s reading?