Describe the software techniques used for improving the signal-to-noise ratio of an electronic system.
See Answer → i) Write down the eigenfunctions for the and
states of the hydrogen atom.
ii) Write the eigenvalues of and
for the states
and
.
iii) Calculate the most probable value of r for the hydrogen atom in the state .
Explain the terms lock range and capture range with reference to PLL. Why is the capture range smaller than the lock range?
See Answer →Explain the working of a shunt regulator using zener diode. What are the limitations of this circuit due to the non-idealities of the zener diode?
See Answer →Draw the circuit of antilogarithmic amplifier using an op-amp and obtain the expression for its output voltage.
See Answer →Calculate the expectation value of the potential energy for the first excited state of a simple harmonic oscillator.
See Answer →Explain the working of an op-amp based full wave precision rectifier with the help of appropriate circuit diagram. What are its advantages over a simple diode rectifier?
See Answer →Show that for any stationary state of a symmetric potential well: .
What are CMRR and slew rate of an op-amp? Explain with examples their effects on the performance of an op-amp.
See Answer → A 1.5 mA beam of electrons enters a sharply defined boundary with a velocity , and then its velocity reduces to
, due to the difference in potential. Calculate the transmitted and reflected currents.
Design and draw the circuit of a non-inverting Schmitt trigger using op-amp with hysteresis of 40% of .
Design and draw the circuit using op amps to solve the following simultaneous equations:
A quantum mechanical particle in one dimension has the wave function:
Use the Schrödinger equation to determine the corresponding potential V(x).
See Answer →Describe the construction of Gunn diode. Explain with the help of E-k diagram the origin of negative resistance region in its I-V characteristics.
See Answer → Draw and explain the equivalent LCR resonant circuit of an oscillating crystal. A crystal has and
. Calculate its series resonant frequency. What is the effect of the crystal thickness on its frequency?
Draw the lead-lag network of Wien bridge oscillator and obtain the expression for its oscillation frequency and required amplifier gain using time domain analysis.
See Answer →i) Normalize the wave function:
ii) Calculate the expectation value of x for a particle in this state.
See Answer → In single ended input – single ended output configuration of a differential amplifier, the input voltage is 10 mV. If the collector resistors , emitter resistor
and supply voltage is
, calculate the differential gain and output voltage of the circuit. Assume that the you are using Si transistors.
Define intrinsic stand-off ratio of a UJT. Draw and explain the I-V characteristic of UJT.
See Answer →Estimate the uncertainty in the energy of a photon localized within a distance of .