94.20: A magnet is dropped through a vewmuq*m*8 ey u bc.(s lx8wpp5+rtical copper pipe slightly larger than the magnet. Relative to the speed it would fall in air, the magnet in the psm(x b*w l.*p wqcup5ymue +88ipe falls:

  01.30: Lenz's law concerning the direction of an induced curr2x5papyq * 9krent in a conductor by a magnetic field could b2 x9ka qr*pp5ye a restatement of

  11.25: The product (l*qna)+q6rv*auu uj ku -3m c83 Teslas) × (2 meters) × (4 meters/second) is equivalent to which one of the 6u)rm +c *qq-3nu 8kv*ua ualjfollowing?

  04.34: A square loop is placed in a uniform magnetic filwbta+6zyq,uo c;w1 . eld perpendicular to the plane of the loop as shown. The loop is 0.5 meters on a side and the magnetic field B has a strengt,t oaw 1; +c.6zwluyqbh 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 wimv+e)e):q ldirected into the page. The wire experiences an induced charge separation as shmeq)vl:e wi)+ own. Which way is the wire moving?

  00.20: A wire moves with a velocity v through a magnetic field and experok.pat5tz - n39la2 hm9-gnahiences an induced charge separation as shown. What is the direcn5p hal9knt -mzht293a g ao-.tion of the magnetic field?

  05.33: The figure below shows a bar moving to the right bzwn8 *;h(b p1 0p ugw2blp bu2woge:9on two conducting rails. To make an induced current ipbwpb*0 bhgu1w ; (9nz8o:p22gwe ulb in the direction 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 magnetic field has a8pcs62ajobb dzj*j :: 1h 3k2ca.ujzf voltage induced between the wirp zjc1.j8aj2ju: fb*b :as23kz6 ohdce’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 rodg8n; z ntn;r h(dp2y6f has constant velocity 0.30 m/s traveling through a uniform magnetic field of 0.060 T. The rod, velocity, and mag;;6g zfy nn(tp 2hnd8rnetic field are all mutually perpendicular. What is the potential difference induced across the rod’s length?

  04.42: A solenoid isfg9eb*h:b rt0 oriented 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 uniformlyt 0:9rb bh*gfe 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 solenoidkt -+de9kpv mk(oqe +3ycx4u2s shown in the diagram (which are assumed to be close to each other), the resistance of th-4x+yq9edkkku( tc+pe m o32ve left-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 ahw/o1;ea rs: b 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 thsbeh; :r1 a/owe 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 thp5- py40ym pt/gtbtuz)m0os( e circuit on the left is -pyu 4mg( t/0osy t)zbtmp5p0increased 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 resistor in the right-hand circuit?

  10.39: A strong bar magnet is held very close to the opening of a sqk8 f /xc-d9jkwji e+6olenoid 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 ckq+ /9w6-kjix8f jedthe 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 otm;-s 3yn)t*h ,vge*c nt3zr 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 the resin-;ryethc)otmnz 3stv g *3*, stance 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 variablejk9kgkl1bro f.l :)d 8 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 resistance of g4mnud ecbklu5mct6*) +.fe*gl .x5 jthe 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 a p .7jdubvru1n3b7g4hb lane 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 inch uv dbbr7gnu.1j47 3brease?

  16.47: Two small loops of wire are located close to a wire with conventional cu ul fzlx36e jx7r:ypfc13y2m (rrent directed up the page. A scientist tx1:czfyljm6 23(ep r x73ulyfhen moves the 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 frictionless condhg8 jr8tazqg9b(3 wpd-:zta / q+g wz6ucting rails as seen in the figure. Throughout the region between the rails, there is azt68jd+8qt qw-9 bzg wa/(3 hrgazgp: 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 the magnitude of the currents through each resistor at the instant shown?

  08.50:. An infinitely long solenoid passes through the circuit a : 7zk gfde5j(apl,vw ;ejn2p8s shown. The magnetic field of the solenoid, directed j7 kj d;2ef(8pn ,:pwlza 5gveinto 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 time 8j nbl.)d+ytv+rzo-i. A constant emf ξ is produced for the square loop e)v.r znly btjd+8i+-onclosing 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 reading?