Chapter 7 CQ

• Figure shows the long straight wire carrying current I to the right and a rectangular loop carrying current twice of magnitude, 2I in clockwise direction. Force acting on a side 2 of a loop is directed:

  In the same direction as current I in the long wire
• Figure shows the long straight wire carrying current I to the right and a rectangular loop carrying current twice of magnitude, 2I in clockwise direction. Force exerted by loop on straight wire is?

  Directed towards the loop and equal in magnitude to the force exerted by long wire on the loop
• Figure shows four arrangements of long straight wires carrying equal in magnitude currents. Wires are equidistant from each other.  

  3; 4; 1; 2

  
• Figure shows three Amperianloops with the direction of walking around them, all currents are the same in magnitude. Rank the values of magnitude of circulation of B for these loops, greatest first.

  2; 3; 1

  
• Consider three wires all caring current I uniformly distributed over the cross-section. wire #1 is of radius R/2; wire #2  is of radius R;  wire #3 is of radius 2R.Rank magnetic field created by these wires at distance R/2 from the center, greatest first:

  1; 2; 3

  
• Consider three wires all caring current of the same uniform density j. Wire #1 is of radius R/2; wire #2  is of radius R;  wire #3 is of radius 2R.

  Rank magnetic field  created by these wires  at distance R/2 from the center, greatest first:

  Field is the same for all