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D 12039 (Pages : 2) 71877೮1138 ........... casesasses

THIRD SEMESTER (CBCSS—UG) DEGREE EXAMINATION
NOVEMBER 2021
Physics/Applied Physics
PHY 3B 03/APH 3B 03—ELECTRODYNAMICS—I
(2019—2020 Admissions)
Time : Two Hours Maximum : 60 Marks
The symbols used in question paper have their usual meanings.
Section A (Short Answer Type)

Answer at least eight questions.
Each question carries 3 marks.
All questions can be attended.

Overall Ceiling 24.

1. Explain Coulomb’s law in electrostatics.
2. Give an expression for the electric field due to a surface charge. Explain the terms involved.

3. How is electric field and potential related in electrostatics ? What is Laplace’s equation in
electrostatics ?

4. Write down the relation connecting polarization and electric field in linear dielectrics. What do you
mean by a polar dielectric ?

5. Write down Gauss’s law in presence of a dielectric.

6. Give the relation connecting permittivity and susceptibility in linear dielectrics. Explain the terms

involved. How is relative permittivity connected to susceptibility ?

7. Check whether the following statements are true or false : (i) stationary charges create constant
magnetic field ; and (ii) a moving point charge cannot constitute a steady current.

8. Give Biot-Savart law. Explain the terms involved.
9. Give the differential and integral forms of Ampere’s law in magnetostatics.

10. Write down the relation connecting magnetic flux density B and magnetic vector potential A.
What is the divergence of A ?

Turn over

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