94.20: A magnet is dropped thhgwdzvjxz,0:5, g *q mrough a vertical copper pipe slightly larger than the magnet. Relative to the speed it would fall in air, the magnet in the pipe djgg,wv* ,5qz zx:m0hfalls:

  01.30: Lenz's law concerning the direction of an induced cujfy 6 5)drozqck)-v s9rrent in a conductor by a-69rzyo 5c)j) kvfdsq magnetic field could be a restatement of

  11.25: The product (3 Teslaslddu:t(7 hw 8x) × (2 meters) × (4 meters/second) is equivalent to which o7 w(dlx:h d8utne of the following?

  04.34: A square loop is placed in a uniform magnetic fi2da tb;8nz8 vbeld perpendicular to the 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 88 zb bdnav2;tloop 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 ma9mpl6pp uy j(-gnetic field directed into the page. The wire experiences an induced charge separation as shown. Which way is the wire moving?(l6pmp pu y9j-

  00.20: A wire moves with a velocity v through a magnetic fiel)gl+nsyu.kl 4yo -7nye7 gwqy8p91g j/xe1ixd and experiences an9ynk/gyu+lwo 8ix4eejqg -y1)g 7.y ls7 1npx induced 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 condch5 58cgsmbpq+v *m/fucting rails. To make an induced current i in the direction indicated, in what directip5b c8 5 hfqc*mgvs/m+on would the magnetic field be in the area contained within the conducting rails?

  00.10: When a wire moving through a magnetic field has a voltu0 4yg8 zre g ;,ey +hi.y*r5rqtn4itiage induced between th, rey5 ; gnyug4*.trhreziqyi0+8i4te 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 hx *zs km+ cb0h kcvqb+w2o:c2(as 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 difference k++hc 2ck cw* ov b(zbx:2m0sqinduced across the rod’s length?

  04.42: A solenoid is oriented end-on so that its opening is perpendicularn-ko5o fgq/5cit8a 8n 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 ton fkg8c/5n i-8q5aopage, 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 assumea 7w,2ivgge)b u9/cpq d to be close to each other), the resistance of the left-hand circuit is slowly increased. In which direct)/ b9g72q ,caiv egupwion does the galvanometer needle in the right-hand circuit move in response to this change?

  08.29: A strong bar magnet is held very close to the opening of a sol 4 ziczz ,nxr;(c,jp1yenoid as shown in tpjr( z1ic xn yz;c,,z4he 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 induced current?

  09.37: For the figure shown, the variable resistance in the circuit on the lbe-4 s e/d 9oi/(wv9c. dvqovbeft 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 what direction is the cwevo9.ivb4d /odec /( b-9vqs onventional current through the resistor in the right-hand circuit?

  10.39: A strong bar magnet is held very close to the opening of a solenoid ashd4t./jerx-2 )rg vh j 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 mage2rv dtrx gj./h4)-jhnetic pole does the “??” in the diagram represent?

  14.34: Two circular loops of resistive wire are placed next to each oth)sm r4.rknp 5p9ppwf6er 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 direck sr .w4ppfm65r 9n)pption 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 resi c*./p-w0caxp a8etcf stance 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 ofxc8cz) x )*eog8rw7ex 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 vuk o92.wj9 cqa plane perpendicular to a spatially uniform magnetic field pointing into the plane of the page as shown. The magnetic field strength steadily incrk 2.9j9wucvoq eases 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 conventional c mki 96ilas8a*p wb-+qurrent directed up the page. A scientist then moves the loops away bw98q6i li - a*+mskapfrom 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 left acrrd ;o;x3ekk) 2jc rck)oss a set of frictionless conducting rails as seen in the figure. Throughout the regioe;;3orxkcdrk j k))2 cn 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 long solenqgy -z 1ftf:a+oid passes through the circuit as shown. The magnetic field of the solenoid, directed into th+yq1t:f zfag -e
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 page0woqsoshc2o 8g29c ei tg-d33 is decreasing 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 ig229ed twsco qho8c3 3-oigs0n it and an ideal voltmeter connected to the corners through the center of the loop. What is the magnitude of the voltmeter’s reading?