Q. 1. (a) Define a line integral and a surface integral Obtain an expression for curl of a vector.
(b) State and prove Stokes1 theorem.
Q. 2. Stat Coulomb’s law of electrostatics. Hence define unit charge. Obtain an expression for energy of a system of charges and a relation between electromagnetic and gravitational force between electron and proton of a H-atom. What is the S.I. system of units and why is it widely used ?
Q. 3. (a) Discuss transient behaviour of a C-R circuit in detail.
(b) Describe a method for finding high resistance by leakage. Why can’t we measure low resistance by this method ?
(c ) A condenser of capacity 0.5 p.F is discharged through a resistance of 10 Mil. Find the time taken for half the charge on the condenser to escape (ioge 2 = 0.6931).
Q. 4. (a) State and prove Gauss’s law of electrostatics. Derive its differential form,
(b) Derive an expression for the electric field at a point inside a uniformly charged solid sphere.
Q. 5. (a) Define the coefficient of mutual inductance and coefficient of coupling.
(b) Give a method for finding coefficient of mutual inductance of two coils. What is the role of the core between two coils?
Q. 6. (a) State Biot-Savart law and hence obtain an expression for the field due to an infinitely long conductor.
(b) Write Maxwell’s equations for electromagnetic field.
Q. 7. Define capacity of a conductor. Derive an expression for capacity of a spherical condenser
(a) with outer surface earthed,
(b) with inner surface earthed.
Q. 8. Write short notes on any two of the following :
(i) em wave equation
(ii) Choke coil
(iii) Dia-, para- and ferro-magnetk substances
(iv) Sensitivity of Wheatstone bridge.