Electromagnetic Field Theory Apr 2013

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Question paper of Pre-University Examination of Electromagnetic Field Theory held at Guru Nanak Education Trust Group of Institution, Roorkee in EVEN Semester Session: 2012-13

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  • 1.info4eee.blogspot.com | AN EEE BLOGGURU NANAK EDUCATION TRUST GROUP OF INSTITUTIONELECTROMAGNETIC FIELD THEORY (TEC-401)PRE-UNIVERSITY EXAMINATIONSession: 2012-13 / EVEN SEMESTERB.TECH (ECE) 2ndYearWrite down your Roll No on the Question paper. M.M. 100Attempt All Questions. Time: 2.30 Hr1. Attempt any four questionsa. If A = 10 ax 4 ay + 6 az and B = 2 ax + ay, find (i) thecomponent of A along ay, (ii) the magnitude of 3A B,(iii) a unit vector along A + 2B.b. Three field quantities are given byP = 2 ax azQ = 2 ax ay + 2 azR = 2 ax 3 ay + azDeterminei. ( P + Q ) X ( P Q )ii. P . Q X Riii. A unit vector perpendicular to both Q and Rc. Given that F = x2ax xz ay y2az , calculate thecirculation of F around the closed pathd. Determine the gradient of the following scalar fields:i. U = x2y + xyzRoll No. +

2. info4eee.blogspot.com | AN EEE BLOGii. V = z sin + z2cos2 + 2iii. F = cos sin ln(r) + r2e. If r is the position vector of a point, then evaluatei. Grad ( r )ii. Grad ( 1 / r )f. Transform the following vector to sphericalcoordinates. The vector is A = 5 ax)2. Attempt any four questionsa. The finite sheet 0 x 1, 0 y 1 on the z = 0 planehas a charge density s = xy ( x2+ y2+ 25 )3/2nC/m2.Findi. The total charge on the sheetii. The electric field at (0, 0, 5)iii. The force experienced by a -1 mC charge located at(0, 0, 5)b. Given the potential sin cosi. Find the electric flux density D at (2, /2, 0).ii. Calculate the work done in moving a 10) )c. Derive dielectric dielectric boundary conditions.d. Explain convection current and conduction current.Derive ohms law in point form.e. Two extensive homogeneous isotropic dielectrics meeton a plane z = 0. For z > 0, r1 = 4 and for z < 0, r2 = 3. Auniform electric field E1 = 5 ax 2 ay + 3 az kV/m existsfor z 0. Findi. E2 for z 0ii. The energy densities (in J/m3) in both dielectricsf. Find the electric flux density at point P (6, 4, -5) causedby a uniform line charge L = 20 C/m on z-axis.3. Attempt any four questionsa. Explain Biot-savart law and amperes circuit law.b. The conducting triangular loop In fig. carries a currentof 10 A. Find H at (0, 0, 5) due to side 3 of thetriangular loop.c. Planes z = 0 and z = 4 carry current K = -10 ax A/m andK = 10 ax A/m respectively. Determine H ati. (1, 1, 1)ii. (0, -3, 10)d. A charged particle of mass 2 kg and charge 3 C starts atpoint (1, -2, 0) with velocity 4 ax + 3 az m/s in anelectric field 12 ax + 10 ay V/m. At time t = 1 s,determinei. The acceleration of the particleii. Its velocityiii. Its kinetic energye. What are inductors? Define inductance.f. Define:i. Magnetic dipole and magnetic dipole moment.ii. Magnetization (M)4. Attempt any two questionsa. Define the following:i. Skin depthii. Intrinsic depthiii. Phase velocityiv. Pointing vectorb. (i) Explain Faraday law and Maxwells equations.(ii) Explain wave propagation in lossy dielectrics. 3. info4eee.blogspot.com | AN EEE BLOGc. How the wave propagation takes place in dispersivemedium? Light is incident from air to glass atBrewsters angle. Determine the incident andtransmitted angles.5. Attempt any two questionsa. Derive transmission line differential equation. Derivethe condition of lossless transmission from it.b. Derive input impedance of transmission line. Definestanding wave ratio?c. Define:i. Reflection coefficientii. Propagation constantAnswers:1. (a)i. The component of A along ay is Ay = -4.ii. 3 A B = 28 ax 13 ay + 18 az.iii. A unit vector along A + 2 B = 0.9113 ax 0.1302 ay +0.3906 az.1. (b)i. (P + Q) X (P - Q) = 2 ax +12 ay + 4 azii. P. (Q X R) = 14.iii. +- (0.745 ax + 0.298 ay 0.596 az)1. (c)1. (d)i. y (2x + z) ax + x (x + z) ay + xy az.ii. (z Sin + 2) a + (2 cos z2/ Sin2) a + ( Sin + 2zCos2) az.iii. (Cos Sin/r + 2) a Sin Sin/r ln(r) a + (CotCos ln(r)/r + r Cosec) a.1. (e)i.ii.1. (f) A = -1.057 ar 2.27 a 4.33 a2. (a)i. Q = 33.15 nCii. E = (-1.5 ax 1.5 ay + 11.25 az) V/miii. F = (1.5 ax + 1.5 ay - 11.25 az)mN2. (b)i. D = 2.5 0 ar C/m2= 22.1 ar pC/m2ii. W = 28.125 J2. (e)i. E2 = 5 ax 2 ay + 4 az kV/mii. WE1 = 672 J/m3WE2 = 597 J/m32. (f) D = (0.37 ax + 0.25 ay) C/m23. (b) H = (-30.63 ax + 30.63 ay) mA/m3. (c)i. H = 10 ay A/mii. H = 0 A/m3. (d)i. a = 18 ax + 15 ayii. u = (22 ax + 15 ay + 3 az) m/s (At t = 1)iii. K.E. = 718 J