Question regarding Magnetic field

AI Thread Summary
The discussion focuses on the transformation of electric and magnetic fields between two frames of reference in motion relative to each other. Participants clarify that 'c' refers to the speed of light and emphasize that the magnitudes of electric and magnetic fields can change due to Lorentz transformations in special relativity. The conversation highlights the importance of dimensional analysis in determining the correctness of the given equations. It is noted that the problem is more about understanding field transformations rather than complex magnetic concepts. Overall, the key takeaway is the necessity of applying special relativity principles to analyze the equations correctly.
utkarshakash
Gold Member
Messages
852
Reaction score
13

Homework Statement


Let \vec{E} and \vec{B} denote electric and magnetic fields in a frame S and \vec{E'} and \vec{B'} in another frame S' moving with respect to S at a velocity \vec{v}. Two of the following equations are wrong. Identify them.

a)B_y ' = B_y + \dfrac{vE_z}{c^2}
b)E_y ' = E_y - \dfrac{vB_z}{c^2}
c)b_y ' = B_y + vE_z
d)E_y ' = E_y + vB_z

Homework Equations



The Attempt at a Solution


First of all I can't understand what is 'c' here. Is it speed of light?Also, how can the magnitude of field change with frame? The magnitude of force can vary but I don't think field should vary. This question seems too complicated to me.
 
Physics news on Phys.org
##c## is the speed of light yes. The magnetic and electric fields transform non-trivially under Lorentz boosts; one can prove this using special relativity. You can probably look it up online if you don't have a textbook that discusses it.
 
Dimensional analysis might be useful here.
 
jtbell said:
Dimensional analysis might be useful here.

Hmm... So its just basically a problem of dimensional analysis. No magnetics involved.
 

Thread 'Struggling to understand the concept of this question (ice cube in water optics question)'

TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
View full post »
Thread 'Variable mass system : water sprayed into a moving container'

Thread 'Variable mass system : water sprayed into a moving container'

Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
View full post »

Similar threads

Field transformations in the z-direction
Replies
7
Views
2K
Magnetic field generated by a current in a wire - special relativity
Replies
1
Views
2K
Why is a current ring approx a magnetic dipole from very far off?
Replies
7
Views
2K
Spring-mediated dipole in a magnetic field
Replies
31
Views
2K
Making sense of sequence of ideas in MIT OCW's 8.02 notes on Faraday
Replies
1
Views
1K
Calculating Area & Direction of Magnetic Field
Replies
9
Views
2K
Direction and magnitude of electric field produced by current change
Replies
8
Views
1K
Calculating magnetic field outside a solenoid
Replies
15
Views
1K
Effect of different magnetic fields on a magnetic dipole
Replies
25
Views
1K
EMF induced in a wire loop rotating in a magnetic field
Replies
4
Views
2K

Hot Threads

Recent Insights

Back
Top