What is the Radial Distance for a Magnetic Field at a 45° Angle in a Solenoid?

AI Thread Summary
To determine the radial distance from the axis of a solenoid where the magnetic field direction is at a 45° angle, the axial and tangential components of the magnetic field must be equal in magnitude. The magnetic field around the solenoid is described by B=Nu0I, while the field around the straight conductor is given by B=(u0I)/(2∏r). Understanding that the axial field aligns along the solenoid's axis and the tangential field circulates around it is crucial for solving the problem. The resultant magnetic field is the vector sum of these two components. This discussion highlights the importance of balancing the two magnetic field components to achieve the desired angle.
11thHeaven
Messages
48
Reaction score
0

Homework Statement


A long solenoid with 10 turns per cm and a radius of 7 cm carries a current of 20mA. A current of 6 A flows in a straight conductor located along the central axis of the solenoid.


Homework Equations


(a) At what radial distance from the axis will the direction of the resulting magnetic field be at 45° to the axial direction?

The Attempt at a Solution


I really don't know where to start here. The only two equations our lecturer has spoken of are B=(u0I)/(2∏r) for the magnetic field around a conducting wire, and B=Nu0I for the magnetic field strength around a solenoid. I can work out the magnetic field strength due to each, but no idea where to start finding out what the "direction" of the resulting magnetic field will be.

Help appreciated! :)
 
Physics news on Phys.org
hi 11thHeaven! :smile:
11thHeaven said:
A long solenoid with 10 turns per cm and a radius of 7 cm carries a current of 20mA. A current of 6 A flows in a straight conductor located along the central axis of the solenoid.

At what radial distance from the axis will the direction of the resulting magnetic field be at 45° to the axial direction?

I can work out the magnetic field strength due to each, but no idea where to start finding out what the "direction" of the resulting magnetic field will be.

45° means that the axial field and the tangential field must be equal in magnitude :wink:
 
tiny-tim said:
hi 11thHeaven! :smile:


45° means that the axial field and the tangential field must be equal in magnitude :wink:

I'm not entirely sure what is meant by the axial field and the tangential field; could you explain?
 
the field along the axis, and the field that goes in circles round the axis :wink:
 
The magnetic field is a vector field. This means that one need to measure its components in 3 directions in order to construct it at any point. The axial measurements give the component along the (z) axis of the solenoid and the tangential measurements will give the other 2 components (x and y) mutually perpendicular to the axial direction. The resultant field in the solenoid will be the vector sum of the two fields, the circular field of the conductor and the axial field of the solenoid.
 
tiny-tim said:
the field along the axis, and the field that goes in circles round the axis :wink:

Great, thanks a lot :smile:
 
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}...
I was thinking using 2 purple mattress samples, and taping them together, I do want other ideas though, the main guidelines are; Must have a volume LESS than 1600 cubic centimeters, and CAN'T exceed 25 cm in ANY direction. Must be LESS than 1 kg. NO parachutes. NO glue or Tape can touch the egg. MUST be able to take egg out in less than 1 minute. Grade A large eggs will be used.
Back
Top