94.20: A magnet is dropped through a vertical copper pipe slightly larger6weyrtf5 :u;-ag5f 92pwmy kl than the magnet. Relative to the speed it would fall in air, the ly- :r2fk6wm;fupta y w59eg5magnet in the pipe falls:

  01.30: Lenz's law concerninpo 3 p,an(xb-;k+ ahvag the direction of an induced current in a conductor by a magnetic field could be a restatement ofx+hk,a3a; ppabvo(- n

  11.25: The product (3 Teslas) × (2 meters) × (4 meters/seg. ae9gd s2jboay4.u (cond) is equivalent to whig4ygj.9o.dsbua e2(ach one of the following?

  04.34: A square loop is placed in a uniform magnetic ;j*vzr) sqduc;dk .i /thv 2.qfield perpendicular to the plane of the loop as shown. The loop is 0.5 meters on a side and the mag dc2jt /v.quds ;ki*) hr.vqz;netic 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 ytmvi*)ypw 3v h):5ho- pxt +na magnetic field directed into the page. The wire experiences an induced charge separation as shownx)* :-v+)m pviytho 3t pwyhn5. Which way is the wire moving?

  00.20: A wire moves with a velocity v through a magnetiie ;+ *q(ypzcbc field and experiences an induced chargebe+ ;qc(i* ypz separation 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 railsj yjyz .vj 7lez2 1et1gqao;;:. To make an induced czq;j2.:e1; a7lyyg jz1tovjeurrent i 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 magn2pkw7r -* nevbetic field has a voltage induced between the wire’s ends, b2 n*kp7v- rewthat 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 twfov 5,wyr fb:t qfw.59sa70 it5;dzrraveling through a uniform magnetic field of 0.060 T. The rod, velocity, and magnetic field are allf q,5;drt5:fz wwrf 0. 9taowisvb y75 mutually perpendicular. What is the potential difference induced across the rod’s length?

  04.42: A solenoid is oriented end-on so that its ov1 v4rd t(.evopening 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 .(4e1 dvo vrtvat 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 assumehv;l*jb. 6mg) qso8bnd 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-han*j 8hvbn qs.olmg);6bd circuit move in response to this change?

  08.29: A strong bar magnet is held very close to the opening of a solel (jnp/ fj54vl4tjn6hk-u6 cm /b7g c f(r-scsnoid as shown in the diagram. As thnj lbcmkl- fvcg-645 jch7psjr(6s /t(n4f /ue 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 direction of the force on the magnet because of the induced current?

  09.37: For the figure shown, the variable resistance in the circuit on theomc1j/86 oa pi left is increased at a constant rate. What is the direction of the magnetic field at the point P 1/o c8pam ji6oat 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 openicov(lwo2:ro +czl)1 .qcql ztwk; (+ing 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 c ;zq w+ vq o1(llcik: loz+twr.c(2o)pole does the “??” in the diagram represent?

  14.34: Two circular loops of resistive wire areii p+gnqgrco68/53rjrir . / e placed next to each other as in the figure. The circular loop on the left is connected to a constant voltage source V.gcp5 j+6n/i ir/eo3qg 8r.i rr The resistance of this loop is increasing linearly with time. As the 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, the variable resisgl fo)0xx/ ji.i gr3-atance 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 resistanceu-*vi/amwl0x ce ati10; 8r ao 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 wiuhr jtu:pns 2b*id 1 -go6s),vg+l 7ddre loop sits in a plane perpendicular to a spatially uniform magnetic field pointing into the plane of the page as shou rg2 hvjb6ont*g-sd u sl1+)d:pdi7 ,wn. 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 wire with conventionalmn/ *o:c kmef0t yop 2j,ir*g3 current directed up the page. A scientist then moves the l jrf 3nkmo t2:e*y*0oip,mgc /oops 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 t:e*/wd/ b)vo. uum ziwt/1tqz he left across a set of frictionless conducting rails as seen in the figure.d/wvo/z:w /u) *q e t1imu.zbt 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 the magnitude of the currents through each resistor at the instant shown?

  08.50:. An infinitely longh6jz fn( 9y55wvvv05vvvu.u*jzi 7eg solenoid passes through the circuit as shown. The magnetic field of the sfzevhuwvvv .5zi6j j57 v5yn*u(g 9v0olenoid, 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 decrj c5n,e;zf2+ox8 /xityzy u-f easing 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 the5xyyf;jietuxf ,z n-8oz +2/c magnitude of the voltmeter’s reading?