Physics (Electromagnetism) - B.Tech 1st Semester Exam-2022
Physics (Electromagnetism)
Instructions:
- The marks are indicated in the right-hand margin.
- There are NINE questions in this paper.
- Attempt FIVE questions in all.
- Question No. 1 is compulsory.
- Symbols used (if any) have their usual meanings.
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Define electric polarization.
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Write down Laplace’s equation.
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Define displacement current.
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What is the physical interpretation of bound charges?
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Define diamagnetism. Give two examples of diamagnetic materials.
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With necessary expression, explain standing wave ratio.
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What do you mean by skin effect?
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Explain the terms motional e.m.f. and transformer e.m.f.
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Differentiate between conduction and convection current.
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What is meant by retarded potential?
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Find the electric field at a distance \( z \) above the centre of a circular loop (radius R) carrying uniform linear charge \( \lambda \).
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Write down the expression for electric field due to surface charge distribution of volume charge density \( \rho \).
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Derive the expression for Transmission coefficient of electromagnetic waves from a non-conducting medium–vacuum interface for normal incidence.
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A point charge \( q \) is situated at a distance a from the centre of a grounded conduction sphere of radius R. Using the method of images, find the potential outside the sphere.
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Explain Faraday cage? What is the electrical force inside a Faraday cage when it is struck by lightning?
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Derive continuity equation for current densities.
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State and derive Poynting theorem.
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Derive the boundary conditions for electrostatic field intensity and electric flux density at (i) the interface between two dielectrics and (ii) the interface between a perfect conductor and a dielectric.
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A long spherical cloud of radius \( r \) has a uniform volume charge distribution of \( \rho_v \). Calculate the potential distribution and the electric field at any point in space using Poisson’s and Laplace’s equations.
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A solenoid of radius 4 mm and length 2 cm has 150 turns/m and carries current 500 mA. Find- (i) \( |H| \) at the centre (ii) \( |H| \) at the ends of the solenoid.
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Determine whether the following potential equations satisfy Laplace's equation or not: (i) \( V = 2x^2 - 4y^2 + z^2 \) (ii) \( V = r^2 \cos \phi + \theta \).
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State Ampere's circuit law. Write its application.
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A hollow conducting cylinder has inner radius a and outer radius b and carries current I along the positive z-direction. Find H everywhere.