Question

pums 2020 Q18. In a certain media with u = Mo, € = 5€, plan wave magnetic field is given by E(y,t) = 15e 0.29 cos(2.7 x 10$t- Byla V/m (6 x 0.5 = 3 marks) Determine: (a) Direction of propagation. (b) Phase constant B. (c) Loss tangent. (d) Intrinsic impedance. (e) Wave velocity. (1) Magnetic field H in the phasor form.

Answer 1

Given Ely, t) = 15e-024 bield L e cos (20 x 108t - By) a Ex=5, l=1 - Solo - The standerd form of electric field of an EM ware. is - = &o é at cos (wt -ß2) ax - (a) Direction of propagation. - Answer ty direction (b) phase constant (B) loss tangent tomo = we put it in above Equation 2= 0.2, w=20x108 rad/sec 02 = 2nxio" vesy (J i teniot - 1)

0:2 = 24 x 10 3x100 / 2 (seco -1) g. 12 x 103 = 5 (se (0-1) seco= 1.00364 Tmor sec²0-1 Tomo =0.0854 © loss Imgent tono = 0.0854 ß= w rue (W116) ²+ ) ) Vita) - 1 Withe)² + 1 - J + Tomo sit tom'o +19 =r seco , ✓ seoti

ale V 1.00364 -1 v1.00364+1 0.0426. ale = ß= 0.2 0.0426 = 4.6928 [B~ 407 (6) phase constant (8) 1 B = 4.7 Answer d Intrinsic Temperature Inl= sq V § - 1200 x 1 V5 ✓it teño seco. 168.595 ma 1.00364 = 167.98 Lon = 0 = 4.8888 = 2044 O= loss longent n = 167.98 22.44

(2) Ware velocity = 0 = 2Txios V = 1-3 + x108 m) sec CJ Magnetic field H Po the phasor form dH=Qk xa E a ây xâx = - hâl # = 10 ore 2024 cos (27x10't -pz -2.44°%) #=0.0892 ē 329 cosan xio*+-B2-274)