Sup. Prob. 24 Key.pdf - Dickey Physics

CHAPTER 241. Assume the current in the wire shown inFigure 24-24 on page 576 of yourtextbook goes in the opposite direction.Copy the wire segment and sketch thenew magnetic field the current generated.2. Assume the current shown inFigure 24-25 on page 577 of yourtextbook goes into the page instead ofout of the page. Copy the figure with thenew current and sketch the magneticfield.i7. A 3.0-cm long wire lies perpendicular toa magnetic field with a magneticinduction of 0.40 T. Calculate the forceon the wire if the current in the wire is5.0 A.F BIL (0.40 T)(5.0 A)(0.030 m) 0.060 N8. What is the force on a 3.5-m long wirethat is carrying a 12-A current if the wireis perpendicular to Earth’s magnetic field?F BIL (5.0 10 –5 T)(12 A)(3.5 m) 2.1 10 –3 N 2.1 mN9. A wire, 0.50 m long, is put into auniform magnetic field. The forceexerted upon the wire when the currentin the wire is 20 A is 3.0 N. What is themagnetic induction of the field actingupon the wire?F BIL, so3. What happens to the strength of amagnetic field around a wire if thecurrent in the wire is doubled?It doubles, because magnetic fieldstrength is proportional to current.4. What happens to the magnetic fieldinside the coil of Figure 24–26 on page577 of your textbook if the current shownwas reversed?The direction of the magnetic field isalso reversed.5. What is the direction of the force on acurrent-carrying wire in a magnetic fieldif the current is toward the left on a pageand the magnetic field is down the page?out of the page6. A 0.25 m long wire is carrying a 1.25 Acurrent while the wire is perpendicular toa 0.35-T magnetic field. What is the forceon the wire?F BIL (0.35 T)(1.25 A)(0.25 m) 0.11 NFB I L 3 N 0.30 T(20 A) (0.50 m)10. What is the size of the current in a 35-cmlong wire that is perpendicular to amagnetic field of 0.085 T if the force onthe wire is 125 mN?F BIL, soF 125 10I –3 N 4.2 AB L (0.085 T)(0.35 m)11. A galvanometer has a full-scale defectionwhen the current is 50.0 µA. If thegalvanometer has a resistance of 1.0 kΩ,what should the resistance of themultiplier resistor be to make a voltmeterwith a full-scale deflection of 30.0 V?V IR, soR V I 30.0V50.0 10 –6 A 6.00 10 5 Ω 6.00 10 2 kΩR T R g R m , soR m R T R g 600 kΩ 1.0 kΩ 599 kΩCopyright © by Glencoe/McGraw-Hill108 Supplemental Problems Manual Physics: Principles and Problems