Tutorial 8 Solution Emagnet

TUTORIAL 8

(SOLUTION)

EEE 3133 ELECTROMAGNETIC FIELDS AND WAVES DEPARTMENT OF ELECTRICAL AND ELECTRONIC ENGINEERING

1. A rectangular loop carrying current I2 is placed parallel to an infinitely long filamentary wire carrying current I1 as shown in Figure 1. The distance between the wire and rectangular loop is ρo. Derive the formula to find the force Floop experienced by the rectangular loop.

I1

I2

b

0

ρ

ρo

a

Figure 1

2. Based on the result obtained in 1, calculate the force experienced by the rectangular loop if I1 = 10A, I2 = 5A, ρo = 20cm, a = 10cm and b= 30cm. Find the force experienced by the infinitely long wire due to the rectangular loop. Ans :      

3. Consider the force between two elements I1 and I2 . The force d(dF1) on element I1 due to the field dB2 produced by element I2 is as shown in Figure 2. Show that the force experienced by the loop 1 due to current loop 2 is                

Figure 2

4. In a certain region (µ=4.6µo),  

!

" #$%&# . Determine the following;

(a) Magnetic susceptibility of the medium. (b) Magnetic field intensity (c) Magnetization Ans : (a) 3.6; (b) '(

!

" )&# (c) *++, 

!

" )&#

5. Given a ferrite material which we shall specify to be operating in a linear mode with B = 0.05T. Assume µr = 50, calculate values of -. / 0 123 4 Ans : 49; 390 00A/m; 796 A/m

6. Assume that µ=µ1 = 4µH/m in region 1 where z > 0, while µ2 = 7 µH/m in region 2 wherever z < 0. Assuming that the boundary between the media is current free, answer the following; (a) Sketch and label the boundary conditions between the two media. (b) In 4 (a), sketch the normal component and tangential component of B in both media. (c) State the relationship between normal component and tangential component of B in both media. (d) Given that 5  +6  (! 7 " #8 in region 1, find the value of B2. Ans : c) 59  59 ; :;  :; ; (d) (6  +! 7 " #8