Download GTU (Gujarat Technological University Ahmedabad) B.Tech/BE (Bachelor of Technology/ Bachelor of Engineering) 2020 Summer 4th Sem 2140909 Field Theory Previous Question Paper

Seat No.: ________

Enrolment No.___________

**GUJARAT TECHNOLOGICAL UNIVERSITY**

**BE - SEMESTER? IV EXAMINATION ? SUMMER 2020**

**Subject Code: 2140909**

**Date:29/10/2020**

**Subject Name: Field Theory**

**Time: 10:30 AM TO 01:00 PM Total Marks: 70**

**Instructions:**

**1. Attempt all questions.**

**2. Make suitable assumptions wherever necessary.**

**3. Figures to the right indicate full marks.**

**Q.1 (a)**State Gauss's law. Also write limitations of Gauss' law.

**03**

**(b)**Define and explain unit vectors in cylindrical and spherical co-ordinate

**04**

systems.

**(c)**Planes x=2 and y= -3, respectively carry charges 10 nC/m2 and 15 nC/m2.

**07**

If the line x=0, z=2 carries charge 10 nC/m, calculate E at (1,1,-1) due

to three charge distribution.

**Q.2 (a)**Define (1) Electric field intensity (2) Potential Difference (3) Potential

**03**

gradient

**(b)**State and prove Stoke's Theorem.

**04**

**(c)**Express the vector

10

=

**07**

+ cos + in cartesian coordinate.

Find vector B at (-3, 4, 0)) 39

**OR**

**(c)**What is an electric dipole? Derive expression for electric field intensity

**07**

and potential due to an electric dipole.

**Q.3 (a)**Derive the relation between current and current density.

**03**

**(b)**Find div D at P (5, /2, 1) if = sin + 32 cos

**04**

**(c)**State Ampere's circuit law and obtain magnetic field intensity due to

**07**

infinite long straight conductor carrying current I using Ampere's Circuital

law.

**OR**

**Q.3 (a)**State and Explain various types of charge distribution with mathematical

**03**

equation.

**(b)**Derive

the equation of continuity equation in integral and differential

**04**

form.

**(c)**State and prove divergence theorem.

**07**

**Q.4 (a)**Explain briefly about lossless propagation of sinusoidal voltages.

**03**

**(b)**Define dielectric strength and list three properties of dielectric material.

**04**

**(c)**Write in details about techniques of controlling EMI.

**07**

**OR**

**Q.4 (a)**List any three effects of EMI.

**03**

**(b)**Derive the capacitance of Co-axial cable.

**04**

**(c)**With the help of equivalent circuit derive the general wave equations for

**07**

the transmission line.

1

**Q.5 (a)**Derive the expression for the force between two differential current

**03**

elements.

**(b)**Write Maxwell's equations in point form and integral form

**04**

**(c)**State and prove Uniqueness theorem.

**07**

**OR**

**Q.5 (a)**Derive Poisson's and Laplace's Equations.

**03**

**(b)**State and explain Faraday's law for statically induced emf with derivation.

**04**

**(c)**Explain magnetic boundary conditions for normal component and

**07**

tangential component.

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2

This post was last modified on 04 March 2021