Short Answer TypeDraw the output waveform at X, using the given inputs A and B for the logic circuit shown below. Also, identify the logic operation performed by this circuit.
Name the semiconductor device that can be used to regulate an unregulated dc power supply. With the help of I-V characteristics of this device, explain its working principle.
Draw the transfer characteristic curve of a base biased transistor in CE configuration. Explain clearly how the active region of the V0 versus Vi curve in a transistor is used as an amplifier.
(i) Define modulation index.
(ii) Why is the amplitude of modulating signal kept less than the amplitude of carrier wave?An electron and a photon each have a wavelength 1.00 nm. Find
(i) their momenta,
(ii) the energy of the photon and
(iii) the kinetic energy of electron.Draw a schematic diagram showing the (i) ground wave (ii) sky wave and (iii) space wave propagation modes for EM waves.
Write the frequency range for each of the following:
(i) Standard AM broadcast
(ii) Television
(iii) Satellite communicationDescribe Young's double slit experiment to produce interference pattern due to a monochromatic source of light. Deduce the expression for the fringe width.
Conditions for Young’s double slit experiment are:
(i) The sources should be monochromatic and originating from common single source.
(ii) The amplitudes of the waves should be equal.
Let S1 and S2 be two coherent sources separated by a distance d.
Let the distance of the screen from the coherent sources be D. Let point M be the foot of the perpendicular drawn from O, which is the midpoint of S1 and S2 on the screen. Obviously point M is equidistant from S1 and S2. Therefore the path difference between the two waves at point M is zero. Thus the point M has the maximum intensity.
Now, Consider a point P on the screen at a distance y from M. Draw S1N perpendicular from S1 on S2 P. 
The path difference between two waves reaching at P from S1 and S2 is given by, 
Since, D >> d, 
Expression for Fringe Width:
Distance between any two consecutive bright fringes or any two consecutive dark fringes are called the fringe width. It is denoted by 
.
Let, 
be the distance of two consecutive fringes. Then, we have
So, fringe width is 
Fringe width is same for both bright and dark fringe.
(a) Describe briefly, with the help of suitable diagram, how the transverse nature of light can be demonstrated by the phenomenon of polarization.
(b) When unpolarized light passes from air to a transparent medium, under what condition does the reflected light get polarized?The energy levels of a hypothetical atom are shown below. Which of the shown transitions will result in the emission of a photon of wavelength 275 nm?
Which of these transitions correspond to emission of radiation of (i) maximum and (ii) minimum wavelength?
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