Quantum Mechanics Answers

If sigma x, sigma y, and sigma z are three components of a pauli spin matrix sigma, then show that [sigma x, sigma y]=2i sigma z; [sigma y, sigma z]= 2i sigma x

If quantum physics formulas are not applicable at subatomic levels, why do we still use them for deriving relations at the subatomic level ?
Ex. if equations of motions are not applicable at subatomic level , why do we use the equations to explain the path of an electron moving perpendicular to electric field ?

4. A boy stands at the centre of a turn table with his two arms stretched. The turn table is set rotating with an angular with an angular speed of 40 r.p.m. How much is the angular speed of the boy if he folds his hands back and thereby reduces his moment of inertia to 2/5times the initial? Assume the turn table to rotate without friction.

What is meant by a well-behaved function ? Illustrate with the help of a suitable diagram.

Consider the potential V(x) = V0. Write down the solutions to the 1D, time-
independent-independent Schrödinger equation when E > V0 and when E < V0.

A particle has the wave function ψ(r) = Ne −ar.where N is a normalization factor and" a " is a known real parameter
Question _calculate the probability of finding the particles in the region of r>Δr

How can we calculate the value of normalisation constant when the electron wave function is given with the range

In an ideal 3:17 step-up transformer, the primary power is 34 kW and the secondary current is 30 A. The primary voltage is:


A. 6.25 V

B. 200 V

C. 1133.3 V

D. 6422.2 V

E. 51 V

Calculate x and x
p for the ground state harmonic oscillator eigenfunction.