In an operational amplifier, the amplifier gain is 10000. The input series resistance is 100\text{ k}\Omega and the feedback resistance is 500\text{ k}\Omega. If the input voltage is 1\text{ volt}, find the exact output voltage and percentage error considering an infinite gain for the amplifier.
Write down London second equation for superconductors. Explain how it accounts for the Meissner effect.
What is a thermistor? Discuss static characteristics of a thermistor. What is its time constant?
Can you comment from the above question whether you can use it to scan surface by microscopy?
Construct a digital circuit to add three bits A, B and C and provide their sum and carry as outputs. Show appropriate Boolean expressions and truth table to justify the outputs.
Explain how the circuit shown above can be a source of oscillations. Use this circuit to construct a transistor oscillator and explain its working. What is the frequency of oscillations of this circuit?
Draw and explain the collector characteristics of a bipolar junction transistor in common emitter configuration. Using the plot, explain how the transistor can be used as an ON-OFF switch.
Show that the London equation \vec{\nabla} \times \vec{J} = -\frac{1}{\mu_0\lambda_L^2}\vec{B} or \vec{j} = -\frac{c}{4\pi n\lambda_L^2}\vec{A} leads to the Meissner effect.
A perfect conductor and a superconductor with T_c \sim 10\ \mathrm{K} are subjected to the following conditions:
(i) cooled under applied magnetic field to 4\ \mathrm{K}
(ii) cooled to 4\ \mathrm{K} and then magnetic field is applied with schematic diagrams, explain path of magnetic field lines in all these situations.
Starting with the expression for the density of states for electrons in a band, show that the Fermi energy of an intrinsic semiconductor is at the middle of the band gap. Use these results to estimate the electron density at 300 K (Assuming E_g=1\,\mathrm{eV} and the rest masses of electron and hole as m_e and m_h).
A crystal plane is shown in the above figure. Find its Miller indices and interplanar spacing.
How magnetic moment and electric quadrupole moment of deuteron indicate the presence of non-central forces in deuteron?
Why was neutrino invoked upon by Fermi and how was it placed into experimental evidence?
What is the importance of the study of deuteron? Discuss the problem of ground state of deuteron and elicit information about nuclear forces from this study.
What is solar neutrino problem and how the phenomenon of neutrino oscillations provides a solution for the problem?
The masses of hydrogen atom and neutron are 1 \cdot 007825\text{ u} and 1 \cdot 008665\text{ u} respectively. Calculate the binding energy per nucleon of {}^{12}_6\text{C} nucleus.
How many fissions take place per second in a 300\text{ MW} reactor? Assume that 200\text{ MeV} is the energy released per fission.
Write down the quark structure of \pi^0, \pi^+, \text{K}^0 and \text{K}^+ mesons.
In the following reactions indicate with an explanation, whether they proceed by strong, electromagnetic or weak interaction or they are forbidden:
(i) \pi^+ \longrightarrow \mu^+ + \nu
(ii) p \longrightarrow n + e^+ + \nu_e
(iii) p + \pi^- \longrightarrow K^+ + \Sigma^-
What is the role of neutrino in the weak interaction of radioactive nuclides? Explain the experimental detection of neutrino.
