Question

A square planar loop of coiled wire has a length of 0.25 m on a side and is rotated 60 times per second between the poles of a permanent magnet. The magnetic field between the poles is 0.75 T. If a peak voltage of 1 kV is generated in the coil, how many turns does it have? 56 turns 25 turns 60 turns 120 turns 1000 turns

Answer 1

a= 0.25m 2 A solution - given's Area = a ² = (0,25) B=0.75T n=6086s so, w=2an aza (60) Epeak I KV TODO V Nano of turns = ? We know & Epeak NABW o N (a ²) (0.75) (2960) N (0.25)?(0.75) (2160) 80 1000 1000 N looo 17.66 N3 56.6 N = 56 twins / approx

2) option (d) the current in the horizontal wire flows to the left and its value is increasing. Is correct because due to current direction in horizontal wire the magnetic field is inside the the plane of circular loop and due to increasing current magnetic field will also be increasing so when EMF is induced it will be induced in counter clock wise direction so as to oppose the increasing magnetic field as counter clockwise movement of current will also create magnetic field in direction outside the plane of circular loop . In this way lenz law is followed.