94.20: A magnet is dropped through a vertical copper pipe slightly larger thzshogr1 jo6+,z176h7hl mi yuan the magnet. Relative to t,1mo7l h76 jihyhz sorg6 z+1uhe speed it would fall in air, the magnet in the pipe falls:

  01.30: Lenz's law concerning the direction of an induced current in a conducto zu q;b8k-n98.jruk9 iniifzp 6+ njh2r by a magne .zzp 8f iuh9bnj8+u -ni6kqrink;j29tic field could be a restatement of

  11.25: The product (3 Teslas) × (2 meters) × (4 meters/secon2;6m (bqy9oxn gx0jzgd) is equivalent to whicho96g ;xj0 gmyqn 2(zxb one of the following?

  04.34: A square loop is placed in a uniform magr2/3wawh ;nwn netic field perpendicular to the plane of the loop as shown. The loop is 0.5 meters on a sidea3nhw2;wn / rw 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 magntbl s-2c0htcp*m u b7ev4ra5:etic field directed into the page. The wire experiences an indutt2:v sc07h5 *p ebalmr- cbu4ced charge separation as shown. Which way is the wire moving?

  00.20: A wire moves with a velocity v thr7w;z)g 0dpc wg tc.n.z- in7qhough a magnetic field and experiences an induced charge separation as shown. What is the direction- w 7c t.zc0p.dg;gnn ih)qwz7 of the magnetic field?

  05.33: The figure below shows a bar kqn*/ qicbx57moving to the right on two conducting rails. To make an induced current i in the direction indicated, in what direction would*xbiq/kc7q 5n the magnetic field be in the area contained within the conducting rails?

  00.10: When a wire moving through a maocsobfb q s+yxes3kf/8(8 8yvy*,dw 2 gnetic field has a voltage induced between the wir(kd8b x*c, +s2vs 8fs3wqoeby o/fyy 8e’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 eqbd8en/;6d/ lk u:lhrn 1u)krod has constant velocity 0.30 m/s traveling through a uniform magnetic field of 0.060 T. The rod, velocity, and magnetic field are all mutuallkrlehndkb:q;/)8 6ule/ un1dy perpendicular. What is the potential difference induced across the rod’s length?

  04.42: A solenoid is oriented end-on soo/svi, 9n wfs3 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 th3w9 v/,snfi soe 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 from brightest to dimmest.

  07.34 For the solenoids shown in the diagram (which are assumed to be close to -y 5/kzhe pkp1each other), the resistance of the left-hand circ/ze kh5-p 1ykpuit 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 9(*6qnt mkifyly pu;5held very close to the opening of a solenoid as shown in the diagram. As the magnet is moved away from the solenoid at constant speed, what is the direction of conve6ny9(f; iqlu5 kmpty* ntional 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 s6-vrj8wlw8;0 r y k4zlcr;bjwhown, 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 lef4yl ;z ;-jrlvb6ckw 80wwrjr8 t-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 3,kueccp-/ yjto 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 resistor shown is directed from A to B. What is the dikc3j pc ,uey/-rection 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 next to each othe xy m5:rb hek+(csurbifak96 5wy( .6or 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 c9hsw( 6ry krm 5(bi6 of ybe.x5u:ak+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 resist+w12x/s a bbxvance 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 the innerciu5t )sp/g+a;v3 a2l:wwxmp ncrcuit $R_{inner}$ 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 ssm*p;8ps- snllq/p 6 6w.:m lpx )gzqfits in a plane 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 thp pf)6gsp*m.s68ll qxz;-mqpw s l:/nis field increase?

  16.47: Two small loops of wire are located close to a wire witg-8+ namzu7ra h 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 r8 zum7-gnaa+ this occurs?

  17.35: A metal bar is ms7j4:m7si8wt nmjbp2e n1 hhf9z 9uc9oving 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 d in1p774s 9z jm9n2 s8ehjcthbu:9w fmirected 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 pmov8 (a3z(9;wniivw p rzaz)a(*k.gpasses through the circuit as shown. The magnetic field of v p9aw(z zw8g r( vnp*;oma3ii(z.)ak 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 page is decreasing in tim* win0 dj k;dvx43cwhk5qa/3ke. 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 in3q4dk0k /vh w35x kndja;w* ic it and an ideal voltmeter connected to the corners through the center of the loop. What is the magnitude of the voltmeter’s reading?