94.20: A magnet is dropped through a vertical cop*6dps o 6c9asjv; 1pypper pipe slightly larger than the magnet. Relative to the speed it would fall in aio*1 s6yppc96a; pjsdv r, the magnet in the pipe falls:

  01.30: Lenz's law concerning thesg/:s x8hdku6 9f 3yz/:uusby direction of an induced current in a conductor by a magnetic field could be a restateuh:dby//zu3s sf6s:g u9 ykx 8ment of

  11.25: The product (3 Teslas) × (2 meters) × (4 meters/second) is equivalent to j3qz4 g ea6i* fren58uwhi6zq *ungee58ajrfi 3 4ch one of the following?

  04.34: A square loop is pmp -yfpnwrbnn+9 3.z8laced in a uniform magnetic field perpendicular to the plane of the loop as shown. The loop is 0.5 meters on a sinbnr 9ym3+znpp8f-w .de 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 fielwpl q4-/;) h xnzqbgf1uj37udd directed into the page. The wire experiences an induced charge separation as shown. Which way is fju7)b l xqun1z -w/p;dq4g 3hthe wire moving?

  00.20: A wire moves with a velocity v bsqmu.uz,ko4a yy7l/78p - me through a magnetic field and experiences an induced cmlbky/ a q-eouyz74s8 p,u. m7harge 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 +vo m47 urntehirp81+k 8me*wconducting rails. To make an induced i muewk8t 4 1*7no+h+e pmvrr8current i in the direction indicated, in what direction would the magnetic field be in the area contained within the conducting rails?

  00.10: When a wire moving through a magnetic field j.nd;vq)oegmp hwq,3 k*ah/9 has a voltage induced between the wire’s ends, hk eq nh9*a).pwdo gvjm,;/3q 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 has constant velocity 0.30 m/s traveling thrj+6i e*2g:mov ble*fx ough a uniform magnetic field of 0.060 T. The rod, velocity, and magnetic field are all mutually perpendicular. What is the potential difference induced across the rod’s lengt 2mj+xi :gb6**ofeelvh?

  04.42: A solenoid is oriented end-on so that its opt aad o8q/;0f2swx4ay 0gaw:wening 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, decreases0ftqx/dg owww;a8a 4sy2aa:0 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 showniq9h: (*dtq ft /mn+uk in the 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 gt f/dt+qqi:9m*u kh n(alvanometer needle in the right-hand circuit move in response to this change?

  08.29: A strong bar magnet is held very close flus7)h;bg 4b3ab+i p 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+4 f3hlb)b7u; aibsgp direction of the force on the magnet because of the induced current?

  09.37: For the figure shown, the variable resistance in the cjfs+nl1z,v 8afrg,uy02t- fgircuit 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 circuitfaj f0-rt1,lunvzs 2yg g+,f8 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 of4- wrr,bj*evi a solenoid as shown in the diagram. As the magnet is moved to the left toward the solenoid, a conventional currenteji 4vrw-*r b, 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 magnetic pole does the “??” in the diagram represent?

  14.34: Two circular loops of k) ro1md; dbeh5ik-+wu ;)j kbti3nf/resistive 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 leftf )wk3eti-k jobudki);; 1/r h+n5mbd-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 resista,d6 ek/+zsjpj bw+wm1nce 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 innetk4o- 6stzgcf q8fy*(nnp+ ( ercircuit $R_{inner}$ 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 ty,j8. r3 ampcoo a spatially uniform magnetic field pointing into the plane of the page as shown. The magnetic field strength steadily increases with time. Which oypm r.a,cj3o8ne of the following effects best describes the result of this field increase?

  16.47: Two small loops of w jtq2s4tvf2a, ire are located close to a wire with conventional current directed up the page. A scientist the 2ts2q4ta jvf,n 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 left across a set of frictionless conductinggb9+ :zwdb1kgcfr 7o) 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 7rz )+k1 c:9bgg owdbfresistors 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 1c-gskh,t 7tp through the circuit as shown. The magnetic field of the solenoid, directed inp, t sk-7cg1thto 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 o c;ow1uge2 qiwci *gl*yr6)5in 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 resirulociigecg;2ww )o 56 *1q*ystance 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?