Explain the construction and operation of Impact Ionization Avalanche TransitTime (IMPATT) diode used for microwave generation.

Explain the mechanical equivalences of L-C-R components of an oscillating crystal. A crystal has C = 0.05 pF, L = 1 H and R= 1 kΩ. Calculate its series and parallel resonant frequencies.

Draw the lead-lag network of Wien bridge oscillator and obtain the expression for its oscillation frequency

In double ended input, double ended output configuration of a differential amplifier, the collector resistors R_C1 R_C2= 51kΩ, emitter resistor R_E = 47 ΚΩ and supply voltage is ± 10V. Calculate the dc collector voltage and collector current in the circuit. For the matched pair of n-p-n transistors with ẞ = 100, calculate the common mode gain of the circuit. What is the advantage of using a constant current source in the emitter circuit of the differential amplifier?

For a common emitter transistor configuration if β = 120, I_E = 5 mA, r_o=∞ and R₁=2kΩ, calculate Zi, AV and Ai.

What are the different pumping methods used in Laser diodes to achieve population inversion? Differentiate between LED and Laser diodes

Draw the circuit diagram of CMOS inverter circuit and explain its working with the help of truth table

With the help of circuit diagram explain the use of UJT as a diode pump stair case generator.

Differentiate between construction and operation of E and D mode of MOSFET.

Explain the construction and working of varactor diode. Write its two applications.

What do you understand by the term reluctance? Obtain an expression for reluctance in a magnetic circuit made of an iron ring magnetised by a current flowing through a coil wound closely over it.

An infinite long wire carries a current 1 A. The wire is bent so as to have a semicircular shape around the origin with radius 1 cm as shown in the Figure below. Calculate the magnetic field at the origin O and determine the direction of the field with respect to the plane of the paper.

Obtain an expression for the dipole moment of magnetic dipole arising due to atomic current in terms of the angular momentum of electron in the atom. Also explain the terms gyro-magnetic ratio and Lande g-factor.

Calculate the magnetic vector potential due to an infinite straight current carrying wire at a point located at distance r along a direction perpendicular to the wire. The current I in the wire is flowing in the x-direction.

Define displacement vector  and deduce Gauss’s law in a dielectric medium.

A charged infinite straight wire having uniform linear charge density λ is placed at a distance b above a grounded conducting plane. Determine the electric potential in the region above the plane using the method of images.

Show that Poisson’s equation follows from Gauss’s law for electrostatics. Write the general form of Poisson’s equation and its solution and apply it for electrostatic potential due to a charge distribution.

A cylindrical conducting rod of diameter d and length /(/ >> d) is uniformly charged such that the electric field near its surface and far from its ends is Eg as shown in the Figure below. The total charge on the rod is Q and the charge per unit length is λ. Calculate the electric field at a distance r (r >> /) from the centre of the rod along its axis.

A mass on the end of a spring, has a natural frequency 2ω , The system is immersed in a fluid that causes the motion to be overdamped,  Γ =  -bq . Obtain the times at which the speed of the mass becomes maximum

Consider a system as given in the figure, where the masses M are fixed and m is the dynamical system:

(i) Write the change in potential for a small displacement.

(ii) Write the change in potential for a small perpendicular displacemen.

Explain whether the displacement is stable or unstable for the two cases.