94.20: A magnet is dropped through a vertical copper pipe slightly5mta -r.-tb: mkwzh5v larger than the magnet. Relative to the speed it would fall in ai v tmh-:5mr tz-abw.k5r, the magnet in the pipe falls:

  01.30: Lenz's law conqd3d2t - jov4/f6ngj9dy guo 7cerning the direction of an induced current in a conductor by a m nj-to3dj 6v9q2 dy u/g4d7ofgagnetic field could be a restatement of

  11.25: The product (3 Teslas) × (2 meters) × (4 meters/second) is equivalentufjt8 jmv b 2vxg4,5jl bf7k 2rcwlf)-q tq19+ to which one of 5uf2l gbj t f-7q)+f1k2j,4 j8tbc9qrl v wxvmthe following?

  04.34: A square loop is placed in a uniform magnetic field perpendicular to tje- v-6 i(wsrphe plane of the loop as shown. The loop is 0.5 meters on a side and the magnetic field B has a strength of 2 T. If the ( r 6jivwpes--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 throw8coq3 e ha/lpf3(c8pugh a magnetic field directed into the page. The wire experiences an induced charge separation as shown. Which way is the wire movopqcfh3ea3cwp l88 /(ing?

  00.20: A wire moves with a velocity v through a magnetic field and: yz1 /u)r80dh.p n7qk bjsvpd experiences an induced charge separation as shown. What is udk1rvszq/:bh 7 pp .)nj8d0 ythe direction of the magnetic field?

  05.33: The figure below shows a bar movin f- l-b+qr earouq8ph2)- r2atg to the right on two conducting rails. To make an induced current i in the direction indicated, in what direction would the magnetic field be in the area contaiq qb+rp-tfr8 ou-h are)-l2 a2ned within the conducting rails?

  00.10: When a wire moving through ao-/qwcq+ cckn mv:21h magnetic field has a voltage induced between the wire’s ends, that voltage isvc q+qkwcm-2h / 1:ocn
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 h88m:d1gvt t2a scez2pas constant 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 differsp2at1 8g2tvemdz 8 :cence induced across the rod’s length?

  04.42: A solenoid is oriented eb7mi s1;kt,u5e i pni,nd-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 uniformly in time at the same rate for each circuit. Rank the circuits for the brightness of the bulb labeled R1 from brie1i pi7;n bi s5km,ut,ghtest to dimmest.

  07.34 For the solenoids shown in7h g/:9luee in the diagram (which are assumed to be close to each other), the resistance o7e e: hl9/guinf the 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 fi)mud.(m*luc4kpp(2 *g ww f magnet is held very close to the opening of a solenoid as shown in the diagram. As the magnet is moved awfmmg . (dfku2w p)*wlcpi( 4*uay 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 i0b;bzk zuytuy .*4rq, ),ex:qyaeed6n 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 whzd:yb) e;,04taezry,y6bkxuuq.eq *at 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 so vps*t) 4g4dfqjndj79 lenoid 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 direcnsqj9 4ftdv)7p*jd4 g tion 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 res*z u:rp6 shpcbm f;*m uk:)o(4/d)/uuyzal h uistive 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 resistance is changing, what is the direction of the magnetic field at point P (the center of the left-hand(:zp dz;m6 /aku) y )4h hocl*buurusf*u:p/m 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 varih-vj:)xb7 vrr a2gx,0wc-vncable 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 the innercirconl h.x7 2-fdouit $R_{inner}$ 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 perpendicular to a spa vnoc 6hz,xm6-tially uniform magnetic field pointing into the plane of the page as shown. The magnetic field strength steadily increases with tinvm-x6z,hoc 6me. Which one of the following effects best describes the result of this field increase?

  16.47: Two small loow+p 3kv(yq4f kps of wire 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 conv( kq4fw v+3ypkentional current in each loop while this occurs?

  17.35: A metal bar is moving to the left across a set of fh5d1wli *sga +fu*1xtrictionless 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 resistoat5w 1gu+h *sfl1 xi*drs 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 t6 lqqk+y 4vr5nhrough the circuit as shown. The magnetic f6l+q 45qrny vkield 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 page is decreasing in tim)xx 3,guhr9iez y. ,kre. A constant emf ξ is produced for the square loop enclosing the fiel3,zx)rhug, rx 9. eiykd 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?