Question

A coil of wire consists of 40 rectangular loops, 16 cm wide, 30 cm high, is placed in B = 0.6 Tx + 0.25 z and 0.2 A pass through it. What is the magnitude and direction of the force exerted by B on the segment ab? What is the magnitude and direction of the force exerted by B on segment bc? What is the magnitude and direction of the torque that is exerted on the coil?

Answer 1

given

N = 40

cd = 16 cm = ab

bc = 30 cm = da

a )

F_ab = N I ( ab X B )

= 40 X 0.2 X ( 0.16 i X ( 0.6 i + 0.25 k ) )

= 8 X 40 X 10^-3

F_ab = 0.32 N along Y - direction

b )

F_bc = 40 X 0.2 X ( 0.3 j X ( 0.6 i + 0.25 k ) )

| F_bc | = 1.56 N

and the direction is

tan = 0.6/0.25

= tan^-1(0.6/0.25)

= tan^-1(2.4)

=67.38^o with X - axis of ZX plane

c)

= M X B

= N I ( A X B )

= 40 X 0.2 X ( 0.16 X 0.3 X ( k X ( 0.6 i + 0.25 k ) ) )

= 8 X ( 0.048 X ( k X ( 0.6 i + 0.25 k ) ) )

=0.2304 j N.m along Y - axis