question_answer 16)

(a) Obtain an expression for the mutual inductance between a long straight wire and a square loop of side a as shown in Figure.                                 (b) Now assume that the straight wire carries a current of 50 A and the loop is moved the right with a constant velocity,  = 10 m/s. Calculate the induced e.m.f. in loop at the instant when  = 0.2 m. Take = 0.1 m and assume that the loop has j large resistance.  

Answer:

(a) Consider a small portion of the coil of thickness dt at a distance t from the current carrying wire.                 Then the magnetic field strength experienced by this portion                 Area of the strip,                  Magnetic flux linked with the strip,                                  Total magnetic flux linked with the coil (within limits from to ) is given by                                                                                 or  ?. (1)                 Comparing eqn. (1) with standard equation                                 we get                 (b) The value of induced emf is given by