94.20: A magnet is dropped through a vertical copper hy+. sygv*qg.( kww9t pipe slightly larger than the magnet. Relative to the speed it would fall in air, the magnet in the pg+*hysvwygt w .qk9. (ipe falls:

  01.30: Lenz's law con8obi6 :f: krapb+eqg.cerning the direction of an induced current in a conductor by a magnetic field could be aq :i68 e+rf:abo.pkbg restatement of

  11.25: The product (3 Teslas) × (2 meters) × (4 meters/second) is equivalent(cmu2( w4hvui94hzs m to which one of the follo2v (s c94imhuh4zmwu(wing?

  04.34: A square loop is placed in a uniform magnetic field3x37yh t8n qfq perpendicular to the plane of the loop as shown. Thq7tf3xq3 n8 yhe loop is 0.5 meters on a side and the magnetic 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 therj;ml+il(2r9i7p jyy+ ;b+rhgwc6pp page. The wire experiences an induced charge sr(gl+hrp wy9; jb; 2i 7jyr+ic+6lppmeparation as shown. Which way is the wire moving?

  00.20: A wire moves with a velocity v through a magnetic field and experiences 0k5 smzf qpzpz9027 fuc*jf3ban zpqf mc025zj*b0 up93 sfkf 7zinduced charge 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 cdl f:est) hv;7onducting rails. To make an induced current i in the direction indicated, in what direction would the magnetic field be in the area contained within thehv:fsed7) ;t l conducting rails?

  00.10: When a wire moving through a magnetic field has a voltage induced btm u; .zg0qef,x;lk(tuia 5q 1etween thel xmeqiazk;.tf5g,1 t( ;u0u q 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 has constan/z wqib3e:(f0drbg:r:wfg e+t 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 potential differenczeq rwdw(e+: /r3bbgi:gf f:0e induced across the rod’s length?

  04.42: A solenoid is oriented end-on so that its opening is perpendij6 x95ch e:ueicular 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 jc965: exh ieurate 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 assumed to be *, /bn:upvahiclose to each other), the resistance of th *vbh /:na,iupe 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 magne( t+o 0qfeka)s9eq6oixf/ sa:t is held very close to the opening of a solenoid as shown in the diagram. As the magnet is moved away from the solenoid ao ffk0)e :a9eois/tsaq6 (+ qxt 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 resistanc8pa wo8taf:v1 e in the circuit on the left is increased at a a8aow vf:8 pt1constant 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 opv l wl6in)d2suq2j7 z5m -c2nxening 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 Ai7lsj u2xnmc5-v wql2z6d 2 )n 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 place2hb;bpquv /drg1b) ;jd next to each other as in the figure. The circ/rv pb)ug1d2 q j;b;bhular 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 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 resistance of the outer 796tdtq85spo- .s mzsn;qybp 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 variabjf)c fiv8uf:,1f+ xjzle 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 wire loop sits in a plane perpendlw*+ /d bryktw4ts0/kicular 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 dwlw / drtk/*04tsk by+escribes the result of this field increase?

  16.47: Two small loops of wire ary9s tn5h 1y8lbe located close to a wire with conventional current directed up the page. A scientist then movesn9syb 85t1 hyl 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 iq qnte4h 24l*bpct+:m s moving to the left 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 conventional current in the resistors and the relation between the magnitude of the currents through each resistor at the instant shown :+ eth44l2b*qcpnq mt?

  08.50:. An infinitely long solenoid passes throtv/k:i o7soe,kw h jr18gqq zfa()*j2 ugh the circuit as shown. The magnetic f) ,we r(f18gs2jva jok7 ozq* ih:q/tkield of 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 the q0/xf * nzy0.xij3d unpage is decreasing in time. A constant emf ξ is produced for the square loop enclosing the field in the figure. The square loop has u3qj 0 zfniyn*xd 0.x/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?