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Questions related from Nityananda Das
Respected All, The size of the COVID-19 virus carrying particles may be less than 2 microns. The gap of knitting of a fabric is larger than this ( As I know) . Then how a fabric mask can...
30 May 2020 7,397 5 View
Respected All To work something regarding protection against Covid-19, I need an information . When Covid-19 is transmitted from one person to other by sneezing or something like this, is there...
15 May 2020 5,815 21 View
Respected All I need a statistical data regarding the size of the Covid-19 carrying droplets. This data is needed for a work related to this. Please help me. Thanks and Regards Nityananda Das
15 May 2020 9,714 11 View
Respected All When a capacitor is connected in a circuit with an AC voltage source , there is displacement current passing through the two plates of the capacitor ( considering parallel plate...
15 May 2020 1,633 0 View
Respected all I need to calculate the resistance between two diagonally opposite points of a spherical object. The resistivity of the material is known. Please suggest me how to calculate...
13 May 2020 2,215 3 View
Refractive index of a material follows the Cauchy Dispersion formula. Again, refractive index is square root of DIELECTRIC CONSTANT. BUT, FOR WATER , DIELECTRIC CONSTANT IS 81, BUT REFRACTIVE...
08 March 2020 7,973 5 View
Mathematically we find that a Gaussian wave packet propagates with a group velocity and the form remains unchanged as it propagates in vacuum. Does this happen in reality? Does there exist...
01 March 2020 1,812 0 View
I need a magnet of strength 5 T. Air gap 5 mm. Air cooled . Is it possible ? If possible , please suggest me the design aspects. Regards and Thanks in advance Nityananda Das
26 January 2020 9,068 3 View
When a material is heated by irradiating em wave ( may be laser, infrared), the random motion of the material ( rms speed) increases. That is phonons are created from phonons. How this process of...
23 January 2020 1,970 3 View
Due to rapid change of e m flux can heat energy be generated ? If not, what is the basic cause of heat generation due to friction ? Regards Nityananda Das
22 January 2020 6,342 4 View
If I consider a circuit consisting of an ideal inductance and ideal capacitance then what can be form of differential equation including the radiation from the circuit ? The initial condition is...
07 January 2020 8,340 1 View
If I consider a pure non resistive L C circuit and excited by an ac current , will the circuit oscillate for ever without loosing any energy ? If happens , how to explain the radiation from the...
17 December 2019 2,648 5 View
In an ac circuit consisting of a resistance and an inductor energy is lost in the resistance by heating and some energy is lost by radiation from the inductor ? How to determine the radiation loss...
17 December 2019 3,818 0 View
By using Schering bridge the ac loss resistance of a capacitor can be determined by calculating tan delta. How can I determine the leackage resistance of a capacitor ? Thanks in...
26 July 2019 4,104 0 View
Silicon is a semiconductor with valance band and condition band shifted along k axis. When an electron in conduction band comes down to the valance band then what happens ? Both phonon and...
19 June 2019 667 2 View
Temperature of a gas is measured in electron Volt. But I don't know how this is converted . Please help me understand.
14 June 2019 3,534 7 View
It is known that three phase lines from a transformer of a distribution line are kept at 120 degree phase angle with each other. What is the need for maintaining this phase differene ?...
13 June 2019 836 7 View
We know the complex plane representation of impedance of L,C,R. If there is a tank circuit, a capacitor in parallel with an L and R and that is connected with an a,c voltage source. Can we...
12 June 2019 6,246 1 View
Can I consider vacuum as a space free from em waves or gravity waves ? If not why such a space can't exist ? And what do we mean by electric impedance of vacuum to to 273 Ohm or something like...
06 June 2019 5,427 3 View
Dielectric discharge voltage of air is 3 KV/ mm. So if two conducting plates are kept with a potential differene of 3kV and placed at a distance of one mm then air discharge will happen. If the...
25 May 2019 2,714 2 View
EM waves are basically vibrating electric and magnetic fields. So it seems that em waves should be deflected by Electric or magnetic fields . But I think it doesn't happen. Please explain the...
22 May 2019 290 5 View
A medium is transparent with respect to one or many bands of em waves. That can be studied by absorption experiment. What physical property lies behind this ? How this is related to permittivity...
22 May 2019 1,379 12 View
When we write Schrodinger equation for delta function potential well problem the potential is written in the form -(alpha)(delta (x) . I think alpha is a scaling factor and then delta (x) should...
22 May 2019 5,998 0 View
It is known that a delta function potential well allows only one bound state and the allowed energy is proportional to the square of alpha ? Regards Nityananda Das
22 May 2019 2,729 0 View
In a crystal atoms are bound by electrovalent bonding or covalent bonding . What is the order of bonding energy in different cases? How we betermine the most favourable crystal structure in terms...
19 May 2019 4,052 3 View
We all know that a delta function potential allow only one energy state when the particle has negative energy. Is there any way connectivity between this delta function potential well and quantum...
18 May 2019 499 0 View
Dear Colleagues, We know that particles with half integral spin ( Fermions ) obey Pauli's Exclusion principle. This needs antisymmetric wave function. WHY FERMIONS OBEY EXCLUSION PRINCIPLE ? Is...
01 January 1970 7,968 5 View
Dear Colleagues, I stated a discussion related to this few days before. Really I am facing the problem . I want to solve the Radial wave functions for Hydrogen atom for degenerate states like n=...
01 January 1970 9,336 3 View
Dear Colleagues, I need to design an electromagnet of strength 4 T by Using Liquid Nitrogen as a coolent. Is it possible to design ? Please suggest the possible design . Should I use any core...
01 January 1970 9,858 4 View
Generally, the standard of a published article is measured by the impact factor of the journal . Is this the correct measure of the standard of an article ? Thanks in advance N Das
01 January 1970 1,449 18 View
Dear Colleagues, Please suggest a very Elementary Book on Finite Element Analysis. Thanks and Regards N Das
01 January 1970 8,741 10 View
Dear Colleagues, I want to transfer Liquid Nitrogen from the container to a Glass chamber. Which type of Glass can be used for storing Liquid Nitrogen ? Thanks N Das
01 January 1970 8,048 6 View
Dear Colleagues, Quantum Defect is a concert of penetration of higher level electrons of an atom into the inner levels. As all electrons , Except 1S , have more than one peaks , each electron ,...
01 January 1970 6,179 9 View
I need an introductory idea of Finite Element Method . Please help me with an introductory idea of this method and some Application Areas that can be handled by this method. Thanks and Regards N Das
01 January 1970 8,875 8 View
Dear Respected Colleagues, What are the main properties that distinguish Particles and Anti-paricles? Please discuss physical properties as well as Mathematical formulation . Thanks and...
01 January 1970 1,920 16 View
Dear Colleagues, Liquid Nitrogen and Liquid Nitrogen container is available in market for doing Low Temperature Experiments. Our Laboratory is a small Laboratory. We are doing Superconducting...
01 January 1970 5,594 4 View
I need to solve the Laplace Differential Equation Del²Φ = 0 and find the electric potential at different points due to a charged plate with uniform surface charge density λ/ m². Dear colleagues,...
01 January 1970 3,943 7 View
Dear Respected Colleagues, I want to create the data file from AFM image file of surface roughness and plot the created data from image as line plotting and surface plotting. This is to visualise...
01 January 1970 9,791 7 View
I want to set up a system of superconducting transition Experiment of YBCO . I want to cool down the chamber holding the sample and four probe and sensor in a controlled way by using a Cryogenic...
01 January 1970 9,598 1 View
Respected All I have generated Plasma in a glass chamber in a low pressure. Can I do Surface Plasmon Resonance Experiment from this ? If it can be done, please suggest me , how can I perform this....
01 January 1970 9,322 2 View
I want to design a Superconducting transition transition Experiment of YBCO. I want to cool down the the glass chamber consisting the sample in a controlled way. Please suggest me how to design...
01 January 1970 6,154 1 View
Dear Respected Colleagues, I am searching for a software for dealing the problems in Physics by Finite Element Method. I was trying by Abaqus but I can find only few modules like Piezoelectric...
01 January 1970 6,930 4 View
Respected All A Gaussian wave packet when propagates in vacuum, whether the wave packet will be broadened and distorted in time or retain its form for ever ? Regards N Das
01 January 1970 7,341 1 View
It is a well discussed idea that moving mass and rest mass are different. m= mo/[1-(v^2/c^2)]^(1/2). Is it correct ? Thsnks in advance. Regards Nityananda Das
01 January 1970 1,775 2 View
Dear Colleagues, We synthesised YBCO and formed a pellet. I have one seen one purchased YBCO pellet which is black. But, our prepared YBCO colour is gray. Can you please tell me the colour of...
01 January 1970 9,788 3 View
Dear Colleagues, I have some brittle samples in the form of PELLET. I want to measure resistivity and some other properties by four probe method. How to confirm the proper electric connection of...
01 January 1970 7,498 2 View
Dear Colleagues, If a heating element is connected to supply voltage of 220 V/ 50 Hz and the circuit is off and on with a frequency of 20 Hertz or 25 Hertz , is there any hamper to the heating...
01 January 1970 4,199 2 View
Dear Colleagues, Can anyone please suggest any low cost method of making electrical contact with a ceramic pellet? I have a YBCO ( Yttrium Barium Copper Oxide) pellet. I want to measure...
01 January 1970 9,454 3 View
I want to calculate the potential difference between two charged plates ( one is positively charged and the other negatively charged ) separated by a certain distance and kept parallel to each...
01 January 1970 1,802 3 View
There are 32 point groups related to crystal symmetry . I don't get the symbols of these 32 groups with the symmetry Elements. It will be better if anyone can help me with matrix...
01 January 1970 4,792 5 View
Dear Colleagues, I want to protect YBCO pellet from direct contact with liquid nitrogen. This is because the bare pellet when comes in direct contact with Liquid nitrogen, there is contamination...
01 January 1970 8,099 5 View
We know materials melts at a certain temperature. ( Not all materials). In different literature it is found that the melting point of this material is this . But , there is highly dependency on...
01 January 1970 4,642 3 View
Dear Colleagues, If I want to get the binding energy of each electron of an Atom, it it possible to get? For example, I am getting BE of 3S electron of Cu to be around 960 eV. But, I want to...
01 January 1970 4,741 13 View
Dear Colleagues, If |0>, |1>, .... are the eigen states of a system, then the total wave function of the system is |Ψ> = A|0> + B|1>+ ...... Thes coefficients mean the weight...
01 January 1970 627 3 View
Dear Colleagues, I want to calculate Electric potential Φ at different points due a uniformly Charged nonconducting disc . So, I need to solve Laplace Equation Del²(Φ) = 0 . Please suggest,...
01 January 1970 4,746 4 View
Dear Colleagues, The polarisability matrix in orthogonal x-y coordinate system is symmetric. But, as I transform the matrix to an oblique co-ordinate system, the matrix is no longer symmetric....
01 January 1970 6,456 4 View
Dear Colleagues, Each time I am sintering YBCO pallet, the levitation is being reduced. More the sintering temperature, the levitation is reduced more. Does it mean, that Levitation is lost...
01 January 1970 3,056 4 View
Dear Colleagues, I prepared YBCO ( 123) heated at 920°C and formed pellet and observed very good levitation. But, after that, I sintered the pallet at 950°C and then the Levitation reduces to a...
01 January 1970 7,068 3 View
Dear Colleagues, I need to measure high ac voltage ( around 10 kV) induced in a secondary coil. Can anyone please suggest any method for measuring this voltage in open circuit and close circuit...
01 January 1970 6,499 3 View
Dear Colleagues, I am trying to design a capacitor by using BaTiO3 as the dielectric. As the dielectric constant of BaTiO3 is about 4000 , I expected that the capacitance will increase 4000...
01 January 1970 3,654 4 View
Dear Colleagues, I am in problem in measuring the transition temperature of a Superconducting sample. I am getting absurd behaviour. I am using four probe method with a disc type pellet. Is it...
01 January 1970 5,483 8 View
Dear Colleagues, I want to use RS Pro Silver Paint ( 186-3600) on a pellet for making electrical contact. Does this paint work at cryogenic temperature? I can't find the service temperature ....
01 January 1970 8,726 1 View
Dear Colleagues, The boiling point of silver at atmospheric pressure is 2162°C. If I want to vaporise silver in vacuum level of 10^(-3) mbar, how much change will be there in the boiling...
01 January 1970 627 5 View
Dear Colleagues It is found that when an electric circuit is switched on or switched off there is a sudden jump of voltage due to switching. Is there any easy solution to reduce the spikes?...
01 January 1970 4,461 2 View
Dear Colleagues, I am using a glow discharge plasma. The average speed of electrons and positive ions are same or different? Please discuss. Thanks and Regards N Das
01 January 1970 481 3 View
Dear Colleagues, I want to perform the transition experiment of YBCO( 123) Superconducting pallet by four probe method. Can I perform this experiment in vacuum of 10^(-3) mbar? Please discuss....
01 January 1970 3,492 2 View
For BH loop study, the vibrating sample magnetometer ( VSM) is used. In stead of using a VSM, if I pass ac current through a long coil and produce ac magnetic field inside the coil, can I get the...
01 January 1970 3,518 1 View
Dear Colleagues, Sintering is the process to make a pallet into a single material. Can anyone please tell me about how to be confirmed that the sintering is done properly and the pallet has...
01 January 1970 4,983 4 View
Dear Colleagues, I want to calculate the Electronic structure distribution and the structure of Simple molecules like H2 , H2O and NH3. I want to calculate by first principle approach. Please...
01 January 1970 7,341 22 View
Dear Colleagues, I want to make a demonstrative experiment on field emission of electrons from metal. How much vacuum level is sufficient for field emission of electron without any corona...
01 January 1970 6,020 1 View
Respected All For a triclinic crystal system the three axes are of different length and the angle between the three directions of primitive cell are not 90 degree. Then is it possible that...
01 January 1970 4,925 0 View
Dear Colleagues, The capacitance of a parallel plate capacitor is given by C = K(permittivity of vacuum) A/d. In this expression, K is real part of Dielectric constant or modulus of total...
01 January 1970 6,601 3 View
Dear Colleagues, Digital Multimeters use constant current source for resistance measurement but Electrometers use voltage source for resistance measurement . Why these two different methods are...
01 January 1970 715 0 View
Dear Colleagues, The resistance between two points on the surface of a disc is measured by passing a current and measuring the voltage drop. Can anyone please explain why resistance measurement...
01 January 1970 506 0 View
Dear Colleagues, The classical form of speed distribution of particles Ac²exp( -bc²)dc is valid for particles in 1D box or not. ? Please discuss. Thanks N Das
01 January 1970 6,150 13 View
Dear Colleagues, I have a pallet of a synthesised dielectric material. The area and thickness of the dielectric is known. The dielectric data set has the following parameters. Frequency, |Z|,...
01 January 1970 6,575 0 View
Dear Colleagues, Working with a composite material whose band gap is found to be 2.5 eV, the Hall effect experiment shows decrease in Hall voltage with increase in magnetic field. Is it...
01 January 1970 1,882 5 View
Dear Colleagues, I am trying to synthesise Bi(1.6) Pb(0.4) Sr(2) Ca(2) Cu(3)O(x) High Tc superconductor. After following the processes of making the Solution, the solution is being heated by a...
01 January 1970 2,726 0 View
Respected Colleagues, The Electric potential and Field produced by an Atomic Nucleus is spherically symmetric. But , except S - States, all others states are not spherically symmetric. The...
01 January 1970 3,804 9 View
Dear Colleagues, I have synthesised YBCO superconducting material and formed the pallet. The levitation is very good. But, after sintering the pallet the levitation is lost . Does this mean...
01 January 1970 2,325 4 View
Dear Colleagues, I need to find the open loop gain of different opamps. Ideally this is infinite,but practically this has a finite value. LM 741, AD620 and AD549 are opamps I am designing some...
01 January 1970 3,542 0 View
Dear Colleagues, I want to synthesize different composite materials by adding different components with desired percentage. What type of furnace is required for this purpose? For example, I...
01 January 1970 6,094 6 View
Dear Colleagues, Please suggest any open source software for ECG signal analysis. Thanks in advance N Das
01 January 1970 3,163 5 View
Dear Colleagues, I want to have a portable Nitrogen Liquefier using Stirling engine by Helium gas refrigerant. Is it possible to design this by purchasing parts ? Are the components available...
01 January 1970 3,175 0 View
Dear Colleagues, A Piezoelectric material is poled along z axis and the dipoles are aligned along Z axis. The poled piezoelectric material under stretching and compressing along Z axis will not...
01 January 1970 7,819 0 View
Dear Colleagues, In one of my YBCO pellets, the magnetic levitation is observed in a very efficient way. But, when I create four contacts by silver paste, the resistance measured between the...
01 January 1970 8,644 0 View
Dear Respected Colleagues, I want to solve the Schrodinger Equation for Helium Atom by Finite difference method to find the wave functions and Energy Eigen Values including the spin orbit...
01 January 1970 2,796 7 View
Dear Colleagues, I want to Synthesise BSCCO( 2223) high Tc superconductor. Bi2Sr2Ca2Cu3O10. Can anyone please suggest me the easiest method for this material synthesis? In Literature, I find...
01 January 1970 4,019 3 View
