94.20: A magnet is dropped through a ver0 a91..wqymzqi ,z 5mwgg. tprtical copper pipe slightly larger than the magnet. Relative to the speed it would fall in m m5 ayw g0w ,ptzz91r.iqg.q.air, the magnet in the pipe falls:

  01.30: Lenz's law concerning the direction of an induced current in a conductor r9fj2:*mo. rov ba j*mby a magnetic field could be a res 9of.rmj:abovmj 2*r*tatement of

  11.25: The product (3 Teslas) × (2 meters) × (4 meters/second) is equivi3v hcaloek :s2k2k :kuxl2e7 -g7gqi83*eboalent to which one *:l2 vkee7 ko 3qk7b8g xa2-3iol:sgiehuc2kof the following?

  04.34: A square loop islhij;d * sj;a5 placed in a uniform magnetic field perpendicular to the plane of the loop asj d5;*lh;isaj 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 magnetic field directed intb6 *b(qtb:uwho the page. The wire experiences an induced charge separ 6:*qbwbt bh(uation as shown. Which way is the wire moving?

  00.20: A wire moves with a veloci hbr xihx ogi6-.xl1+-ty v through a magnetic field and experiences an induced charge separation as shown. What is the direction of theli.bxh 1i 6-xr-x+ogh magnetic field?

  05.33: The figure below shows a bar moving to tovz;aak h2r7(x803r f 7 qenxr)ogut1he 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 contai ho;nrgaxue0kv1(trq z2 o7 afx r738)ned within the conducting rails?

  00.10: When a wire moving through a magnx sc ro1y)5pe8+t gk1ietic field has a voltage induced between the wire’s ends, that volta81 ex)rc5igp+y1tok sge 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 0.3q j(suf)v 8*vh0 m/s traveling through a uniform magnetic field of 0.060 T. The rod, velocs h (j)*uqfvv8ity, and magnetic field are all mutually perpendicular. What is the potential difference induced across the rod’s length?

  04.42: A solenoid is oriented end-on so that its opening is perpendiculcdbvyivfm u3vo/2y6 c):.4 wzar 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 v. c6wv fu2oy)m vb/43ycizd: 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;kw5iy6:u5 a6mdkm bn diagram (which are assumed to be close to each other), the resistance of 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 d55yka;wu:n6 bkm 6mi?

  08.29: A strong bar man;0 4cyx6 wttagnet is held 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 conventional current through the resistor shown and what is the direction of the force on the magnet because of the induced ct x06w;4t yacnurrent?

  09.37: For the figure shown, the variable resistance in the circuit on the le.fg1d iwc .qd7ft 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 add7.wi c1 g.qfnd in what direction is the conventional current through the resistor in the right-hand circuit?

  10.39: A strong bar magnet is held very hay-;(o3qfkvsf+bs (close to 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 direction of the force on the bar magnet because of the induced current in the solenoid and whfkhy3 qs((-oaf+s bv; ich magnetic pole does the “??” in the diagram represent?

  14.34: Two circular loops of resistive wire are placed next to each other agy zagc mb*ny,*c,c 4:s 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 right-hand loop (as viewed in tc**,cmb:4g czny ga,y he figure from above)?

  11.41: For the figure shown, the variable resistance of the ma,s26s 23l3blv hja kouter 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 resistanu6(m;i; i3w0pu gu oqjv i81vvce 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, cond c n6cp3fi)pd6ucting wire loop 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 of the following eff)p36 p6i cfdcnects best describes the result of this field increase?

  16.47: Two small loohlv 6,n mhk)b5ps of wire are located close to a wire with conventional current directed up the page. A scientist then moves tb 5v,nl hm6)khhe 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 tfah,6gv bhp)b a( /0heo 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 f60)e/(hfh bhb, vaap gield 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 solenoid passes through the circuit as w1 kzp0*.ngqh)z x.tgshown. The magnetic fieldwhtzx.gpnq1 )g.0 zk * 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 o;.t+ mhcs svj/f the page 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 in it and an ideal voltmeter connected to the corners through the center of the loop. What is the magnitude of the v/cvsjs;.hmt + oltmeter’s reading?