# SASTRA University 2010 B.Tech Electronics and Communications Engineering First Mid Term Electromagnetics - Question Paper

Wednesday, 30 January 2013 01:00Web

**Part A**:

1.A point in spherical coordinates is at (5,60°,150°).Express its position in rectangular and cylindrical coordinates.

2.write down Gauss Divergence theorem and stroke's theorem.Also provide the 2 vector null identities.

3.derive the formula of continuity.

4.Express Maxwell's divergence equations in the differential and integral forms.

5.A conductor 1m length in parallel to the Z axis and rotates at a radius of 25 cm at 1500 rpm.Find the induced voltage if the radial field normal to the plane of rotation is provided by B=0.6ax wb/m²

6.Define m.m.f.

**7.**A parallel plate capacitor with plate area A cm² and plate separation of d mm has a voltage V applied to its plates .Show that the displacement current equals the conduction current .

8.What is a time harmonic field? Express Maxwell's equations in phasor form.

9.Find the value of to satisfy Maxwell's equations foe the provided fields E=(kx-100t)ay v/m and H=(x+20t)az A/m if µ=0.25H/m and ?=.01 F/m.

10.Compare conduction current with displacement current.

**PART B**

ans any 3 questions:

11.Obtain the general relation for the total induced emf under the 2 conditions.

12.Explaining the need for modifying Ampere's legal regulations arrive at Maxwell's formula.Bring out its siginficance.

13.Derive Poynting's theorem giving relevant interpretation for every term involved in it.

14.Obtain the Boundary Conditions for the normal and tangential components in the case of electric field .

Earning: Approval pending. |