94.20: A magnet is dropped through a vertical copper pipe hx ww, b0y)hk4slightly larger than the magnet. Relative to the speed it)wxk4hy,hw 0b would fall in air, the magnet in the pipe falls:

  01.30: Lenz's law concerning the dir*dcc7if0.p ev* k4uwu ection of an induced current in a conductor by a magnetic field could bew ku0pc dv*ei4f.7*u c a restatement of

  11.25: The product (3 Teslas) × (2 meters) × p dbn*r*jjc; o.-uzp7(4 meters/second) is equivalent to which on ;ur*np7jd-bj*o c. pze of the following?

  04.34: A square loop icmnxv(. ew)6 sp(7ib is placed in a uniform magnetic field perpendicular to the (ivb6xwc ) (sm 7i.npe 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 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 8zdklwq4;gd17rngb r n) eg24 magnetic field directed into the page. The wire experiences an induced charge separation n q2rz)bge; krd4n178w 4dlgg as shown. Which way is the wire moving?

  00.20: A wire moves with(c d-//t i2auqdaov r+ a velocity v through a magnetic field and experiences an induced charge separation as sh id-ardtu/ a(v/+2 cqoown. What is the direction of the magnetic field?

  05.33: The figure below enwx k5zb:n ;ao..m0 u5eb0l eos7-fn shows a bar moving 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 ;bnees0n.7fxe. wnboamo-kl5: u0 5z the area contained within the conducting rails?

  00.10: When a wire moving through a magnetic field has a voltage induced betweentponau/s)021 mnsg v1tll59 n the wire’s ends, that slg 5vtl2u91 /po)nt10 n ansmvoltage 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 taf sn+rf98ha)cev:9u)ah y-zxjt4r 3raveling through a uniform magnetic field of 0.060 T. The rod, velocity, and magnetic field are all mutually perpendicular. What is the potential difference induced acro8 +r rxahsv)jt u9h:9y)4-z ceaan 3ffss the rod’s length?

  04.42: A solenoid is oriented end-on so that its opening is perpendiczb-przg:-jk v*sm7 b nqd4 20tular 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 label4jkzg2n7b:-r mb z-ptvqds 0*ed R1 from brightest to dimmest.

  07.34 For the solenoids shown in the diagram (which are assumed to be closeddfj(6r x,7 pe to each other), the resistance of the left-hand circuit is slowly increased. In which direction does the galvanometer needle 7(dd pr,xe6fjin the right-hand circuit move in response to this change?

  08.29: A strong bar magnet is held very close to the opej5 j d0y9cev4+z6nmsoning 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 conventional current through the resistor shown and what is the direction of the force on the magnet because of the ve 0jzoc5dy+nm s64j9induced current?

  09.37: For the figure shown, the 6dyob ie f qg8((j(ynfd f5x)1variable 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 cniy 8e( do1yfqd5bx((6 jffg)enter 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 solenoidn bq0rz;wke: in8(j 9krs bu;u*d7rx v: ee02q 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 curres*90 jn:zr 8ee2xw:;0idvq(une; kbb7r ru qknt 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 v4bt1d4f )u4 (rzcpl 2t9qqm yeach 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 loop) and what is the orientation of the conventional current in the(rdmqu4 4t2b9p ytqf4cz1 )vl right-hand loop (as viewed in the figure from above)?

  11.41: For the figure shown, the variable resistance of the out+0rhg rrgm59a .t ++gnmhxwv; er 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 innercircui+ c9nrz d60rjit $R_{inner}$ 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 loopryq)ixozm *sbg734 )in;r 8hc sits 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 igq7s4n iz3mrc 8xy )bho*;)r 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 q2i .16oedm,jsjtymnczn4) -conventional current directed up the page. A sciene1z4q2i. 6mty nsn)j, djm-c otist then 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 lefteoa(8(,eprv o 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(p ea8v,er(o o 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 2) ir sb 5h;i;hbsb:ugthrough the circuit as shown. The magnetic field of the solenoid, d r : shsib2bbg5;uih;)irected 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 timlo/9n0 v pa3h maa*snf:dn49de. 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 throughv4/3 afpnh ml09sna9:odda *n the center of the loop. What is the magnitude of the voltmeter’s reading?