# Search results

1. ### Tesla's Experiment

I am doing a very amateur version of Tesla's experiment of using potential difference between positively charged sky ( due to solar wind) and negatively charged earth. I took a piece of cardboard. Stapled aluminum foil to it to use as antenna. Stapled stripped end of wire to this foil and hung...
2. ### Eigenvalues of a complex symmetric matrix

Eigen values of a complex symmetric matrix which is NOT a hermitian are not always real. I want to formulate conditions for which eigen values of a complex symmetric matrix (which is not hermitian) are real.
3. ### Path of current functional

Current follows the path of least resistance or shortest path. I just want to prove this or rather reproduce it using calculus of variations. I just want to show it in a fancy way. I want help to form the FUNCTIONAL for it. Useful equations: I=dq/dt=nqvA R=rho*l/A Where v is drift velocity...
4. ### Russian Roulette and schrodinger's cat

We all the famous schrodinger's cat experiment and its outcomes which sound stupid in classic or macroscopic world. A similar thought came to my mind for Russian roulette game. Suppose you lock 2 game players in a room with a revolver of single shot and they start playing Russian roulette by...
5. ### Ripple equation

I want to formulate an approx 2D ripple equation μ(x,y). It should satisfy following: 1) it should have highest amplitude on y axis at x=0. It should be symmetrical about y axis. It should fade away at some x on both positive and negetive x axis symmetrically. Fading in a way of decreasing...
6. ### Linear Algebra for QM

I was going through Linear Algebra which is recommended as a prerequisite to Quantum Mechanics. The topic of LA is vast and deep. So I wanted to know which (specific) topics of LA should be covered as a prerequisite to QM.
7. ### Mathematical tools for quantum mechanics

I am currently reading the book on quantum mechanics by N.Zettili. It's really a good book but has a lot of mathematical stuff which I am not able to absorb. There's a whole chapter on mathematical tools but it is difficult to.understand. Can anyone suggest me book or text on mathematics as...
8. ### Gravitational lensing due to earth

It is known that light from stars bend near surface of sun due to its mass. Similarly light will bend near earth's surface (may be insignificant due to less mass). My question is that sunlight that strikes earth's surface travels a straight path from sun or a curves near earth's surface ?
9. ### Physics Investment for Physics Degree from a foreign country

I am from India and I am currently studying Electrical Engineering from a good private college( with a considerable CGPA of 8.5). But I was never interested in Engineering. All I wanted to go for was Pure,Basic and theoretical Physics. Many "experienced" people advised me to do engineering and...
10. ### Impact Parameter

Any problem of collision can be solved using four equations: Conservation of momentum and energy, impulsive forces and impact parameter (distance between center of masses of the particle taken perpendicular to velocity). I can solve problems using first three cases. But how to analyse a problem...
11. ### Two Capacitors Problem

Homework Statement Two capacitors C1=4μf, C2= 12μf are connected in parallel across 12V battery. Then they are collected in parallel, with positive side of one capacitor to the negative side of the other. Find the resulting potential difference. Answer (as on back-pages): 3.50V...
12. ### Entropy change of universe

Homework Statement A system absorbs 200 J of heat from a reservoir at 300 K and rejects 100 J to a reservoir at 200 K as it moves from state A to B. During this "NON-QUASI-STATIC" process 50 J of work is done by the system. What is Entropy change of universe ? The Attempt at a Solution...
13. ### Final Equilibrium Temperature

Homework Statement An adiabatically isolated system consists of 1 mol of a diatomic gas 100K and 2 mol of a solid at 200K separated by a rigid adiabatic wall. Find the equilibrium temperature of system after adiabatic wall is removed, assuming that the solid obeys the Dulong-Petit law...
14. ### Carnot refrigerator and II law of Thermodynamics

As per II law of thermodynamics you it is NOT possible that a hotter body becomes hotter and colder body becomes colder when in contact. But in a Carnot refrigerator, the heat is taken from a cold reservoir and pushed to a hotter one. It sort of opposite the II law. Help me over this paradoxical...
15. ### Zero Efficiency Machine

Lets say if we have an induction motor or any motor whose rotating shaft acts as a source of alternating emf to another motor and rotating shaft of this motor again acts as a source of alternating emf to third motor and so on... We connect such a finite number of motors and we call it as a...
16. ### Size of cavity on expansion

There's a metal plate with a circular hole/cavity in it. Consider its width negligible. Now the plate is uniformly heated. Textbook says that size of hole/cavity increases along with the dimensions of the plate. But my intuition says dimensions of cavity should increase and size of hole/cavity...
17. ### Period of oscillation (potential energy equation given)

Homework Statement Let the potential energy of particle depend upon coordinate x as: U(x) = U0(1-cos(ax)). Where "U0" and "a" are constants. Find the period of small oscillations that particle performs about its equilibrium position. 2. Given Answer T = 2∏√(m/a2U0) The Attempt at a...
18. ### Electric field between electrodes of half-filled spherical capacitor

Homework Statement Half the space between two concentric electrodes of a spherical capacitor is filled with uniform isotropic dielectric with permittivity ε. The charge of the capacitor is q. Find the magnitude of electric field strength between the electrodes as a function of distance r...
19. ### Neucleophilic Acyl substitution of unsymmetrical Acid Anhydrides

Consider the following reaction: RCOO-COR + R'-OH → RCOO-R' + RCOOH (where -R is an alkyl group) In above reaction the acid anhydride and an alcohol forms ester and carboxylic acid. The acid anhydride used in this case is a symmetrical on that is containing only one alkyl group (R)...
20. ### Values of Velocity at which the body will move without bouncing

Homework Statement A small point mass is fixed to the inside of a thin rigid ring(hoop) of radius R and mass equal to that of the point mass. The hoop rolls without slipping over on a horizontal plane; at the moments when the point mass gets into lower position, the center of the hoop moves...
21. ### Acceleration of the center of mass

Homework Statement A body of mass m, moment of inertia I, radius R is rolling (without slipping) upon the action of force F applied in horizontal direction at a distance x above center of mass (com). Prove that acceleration of com (a) = F[(1+(x/R)]/[m(1+(I/mR2)] Homework Equations F -...
22. ### Force exerted by a rolling body

Lets consider a block of mass m, sliding down an inclined surface (no friction) at an angle ∅ with ground. The force exerted by this block on the inclined surface is mgcos∅ which is perpendicular to it. Now consider a cylinder of same mass m and rolling (without slipping) down the same plane...
23. ### Application/use of reduced mass in conservation of momentum/energy problems

I want to know in which types of problem this reduced mas μ=m1*m2/(m1+m2) is used . All i know that it is closely related to center of mass of the system but don't know exactly where to use it?
24. ### Choice of reference frame in conservation of momentum/energy problems

Problems related to conservation of momentum/energy can be solved by taking reference frame which is stationary to center of mass or which is stationary to ground/observer. So when to use what frame or which frame is beneficial in which case/type of problems? I m confused !:confused:
25. ### Schools Best university for UG degree in physics with low fees and low cost of living

Which is the best university for undergraduate degree in physics with low fees and low cost of living?
26. ### Removal of dielectric from a charged capacitor.

There is a parallel plate capacitor having capacity C. It initially has got no charge on it. Now we insert a dielectric material of dielectric constant K between its plates (it still has no charge). Now we connect this capacitor (with dielectric) to a d.c source of potential difference V. Now...