Related InterviewSolutions

• A wide copper strip of width l is bent into piece of slendder tubing of radius R with two plane extension as shown (Fig. 1.12). A current I flows through the strip, distributed uniformly over its width. Ib this way, one-turn solenoid has been formed (a) Derive an expression for the magnetic field in the tubular part.
• What pressure does the lateral surface of a long straight solenoid with n turns per unit length experience when a current I flows through it.
• A current `I` flows in a long single layer solenoid with cross-sectional radius `R`. The number of turns per unit length of the solenoid equals `n`. Find the limiting current at which the winding may ruputure if the tensile strength of the wire is equal to `F_(l i m)`.
• A current `I` flows in a long thin walled cylinder of radius `R`. What pressure do the walls of the cylinder experience ?
• A unifrom current of density `f` flows inside an infinite plate of thickness `2d` parallel to its surface . Find the magentic induction induced by this current as a funcition of the distance `x` from the median palane of the plate. The magnitude permeability is assumed to be equal to unity both inside and outside the plates.
• A this disc of dielectric material, with a total charge +q distributed uniformly over its surface, rotates with angular speed `omega` about an axis perpendicular to the disc and passing through its centre .Find the magnetic moment with its angular momentum , assuming that its mass is m. [Hint : Consider a ring of radius x and thickness dx. Calculate charge on it and then the current consituited by its rotation .Find its magnetic moment and integrate for the whole disc.]
• Electric charge +q is iniformaly distributed over the entire volume of a sphere of radius r. Calculate the magnetic moment of the sphere if it spins about its diameter with angular speed `omega` . Compare this moment with its angular momentum, assuming that its mass is m.
• A ring of dielectric material, with a total charge +q distributed uniformly over its surface, rotates with angular speed `omega.` Find the magnetic moment of the ring .Compare its magnetic moment with its angular momentum , assuming that its mass is m.
• Two currrent elements `2 xx 10^(-4)` A m and `5 xx 10^(-4)` Am are placed at the vertices A and B of an equilateral triangle along AB in the same sense. Calculate the magnetic field at C. (Each side of the triangle measures 10 cm)
• A long cylindrical conductor of radius a contains a long cylindrical holr of radius l. The axes of the two cylinders are parallel and are at a distance d apart. A current I is uniformly distributed over the cross-section. Find the magnetic field at the centre of the hole. [Hint: Apply the principle of superposition of magnetic field]