Oho.. And since r hat is varying I can't take it as a constant under integration.. That's why we convert the spherical system to cartesian one.. Where the unit vectors are independent of the angles.. And that was the point of this exercise.. To teach us to consider the constancy of unit vectors...
Question : Find the electric field at the centre of a ball of radius R with volume charge density rho = a.r, where a is a constant vector and r is a radius vector drawn from ball's centre.
Relevant Equations and attempt at solution : I used the basic formula for electric field due to...
Hello everyone
I need to do a write up for VSRP 2016. The summer research programme at TIFR,India.I am interested in Physics programme. I have never done a write up so I am not sure what to write.They mention that I should explain my interest areas but discourage strongly to write equations.They...
I tried to calculate the efficiency of a engine using the formula :
Efficiency = (Net Work Done) / (Heat absorbed)
And then I tried to calculate the efficiency of respective Carnot engine by two ways :
1) Efficiency = (Net Work Done) / (Heat absorbed)
2) Efficiency = 1 - (Temperature Lowest /...
Homework Statement
In the twin paradox suppose the twins are named Dick and Jane. And they both are 20 years old.Dick takes off on a voyage at a speed of 0.8c to a star 20 light years away.Lets say that both the twins send each other signals once a year while Dick is away.How many signals does...
According to Fermat's Principle (modified version) a light ray takes an extremum path. Can anyone explain the physical reason behind this? I mean, sure the light can take the least path but how can it take the longest path? And if it can indeed take the longest path, why not the paths shorter...