94.20: A magnet is dropped through t/tsl4xf y3 6.uzb v)v,i5mcfa vertical copper pipe slightly larger than the magnet. Relative to the speed it would fall in air, the magnet in the pipe f vyl.ix6 mu /b,c43t zsft5v)falls:

  01.30: Lenz's law co-dhq051u tg*u( rrnmincerning the direction of an induced current in a conductor by a magnetic fu gdnr1 hu-tqi*r0m5( ield could be a restatement of

  11.25: The product (3 Teslas) × (2 .-dfv0vbz f80jh pc;k meters) × (4 meters/second) is equivalent to which one of the foll 0jcv ;zkdh-vf.0 8fbpowing?

  04.34: A square loop is placed in a uwpkyqjq0muspwo5) 5+;)y .rh: ggi1 ghua:.d niform magnetic field perpendicular to the plane of the loop as shown. The loop is 0.5 meters on a side and the magneticiyp. y;h: 0ah w5u:ow.)+pd )1gruqsgmk5gqj 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 into the page. The wire efw035w y( m ;;rbq1unhhwfbv 6xperiences an induced charge separation as shown. Which way is the w;(6 hfnu 1br35w 0;qmvbww yfhire moving?

  00.20: A wire moves with a velocity v through a magnetic field and exvia ub8.hr (,bperiences an induced charge separation as shown. What is the direva. b 8hbui(,rction of the magnetic field?

  05.33: The figure below s)qk1dg e6;ldnew i+i4hows a bar moving to the right on two conducting rails. To make an induced current i in the direction indicated, in what direction would the m4di+en dl iq )gw6;ke1agnetic field be in the area contained within the conducting rails?

  00.10: When a wire moving through d;6y q6cl+whq a magnetic field has a voltage induced between the wire’s eldyqh6 +;cq 6wnds, 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 constant velocity 0.30 m/s traveling throu7vt(qy in 0b7zgh a uniform magnetic field of 0.060 T. The0 bqv(yzti77 n rod, velocity, and magnetic field are 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 perpentz ,lly-m/t+x jxa b.( fi-r)gdicular 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. Rank the circuits for the brightness of the bulb labeled R1 fr+. r/t-yjxlf-i)tl( gbazxm, om brightest to dimmest.

  07.34 For the solenoids shown in tj-quf)x -cn .the diagram (which are assumed to be close to each other), the resistance of the lqfuj) ct- .-nxeft-hand circuit is slowly increased. 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 of a /zt:d mw-u cb*wf4n2asolenoid 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 directu w/:aw*t 2bm4z-dc fnion of the force on the magnet because of the induced current?

  09.37: For the figure shown, the variable ae1lcq*lq)o ixt o;462fp)nm 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 and in what direction is the conventional current through the reom i2a npt)*6lqc) e1oqf;x l4sistor in the right-hand circuit?

  10.39: A strong bar magnet is held very close to the opening of a solen 4c8ahhcv9ubr ,3a.wa oid as shown in the diagram. As the magnet is moved to the lefth r ,a9va8 3.hcucba4w 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 diagram represent?

  14.34: Two circular loops of resistive wire are placed nex; 8bor4 wled;h,z zm+lt 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 the resistance is chazb ;+ mhw4e l,ro8;dzlnging, 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 figur pfcw,w5vqius9.e5m ; x5d3roe shown, the 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 sho*h6 7dv)ss 1ceoml kj/wn, the 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 (c*f;q,ww *umeovz 0jr 5.nbf 23kqxhwire loop sits in a plane perpendicular to a spatially un 25nq*, mwbwzhkvr3cx(* 0joffu; q.eiform 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 (;9,yqhj.bqoi nqr 3 vrs ((abwire 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 the conjvr yabq 9,(o.rq binq((h3 ;sventional current in each loop while this occurs?

  17.35: A metal bar is moving to the left avm7 rgf).:x k9(fwaat cross 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 conventional current in the resistors and the relation between 7 fwgfa k(vam. tr)9:x the magnitude of the currents through each resistor at the instant shown?

  08.50:. An infinitely long solenoid passes through tz 6z* mk()pmv3afka :she circuit as shown. The magnetic field of*(fv)a: z km 3mpask6z 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 thcvrz.xb( vz+/ e 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 the magnitude of the voltmeter’s rea +zcrzbvx/ v(.ding?