Question about magnetism/induced emf in small coil

  • Thread starter Thread starter nwyatt
  • Start date Start date
  • Tags Tags
    Coil Emf
AI Thread Summary
The discussion centers on calculating the induced electromotive force (emf) in a small coil placed within a solenoid. The solenoid has specific dimensions and carries a current that is switched off, leading to a change in magnetic flux. The magnetic flux through the small coil is initially calculated to be 14.4 x 10^-6 Weber, and when the current is turned off, the flux decreases to zero. The change in magnetic flux (delta Φ) is therefore 14.4 x 10^-6 Wb. The induced emf can be determined using the formula, considering the time interval of 25 ms for the current switch-off.
nwyatt
Messages
5
Reaction score
0

Homework Statement


A solenoid with a length of 25.0 cm, radius 1.60 cm and 5500 turns carries a current of 1.50 A. A small coil of radius 1.05 cm and 130 turns is placed at the center of the solenoid with its axis in the same direction as that of the solenoid. A 470 ohms resistor is connected to the ends of the small coil. The current in the solenoid is switched off within 25 ms.

Determine the magnitude of the induced emf in the small coil.

Homework Equations



Induced EMF= -N delta \Phi / delta t

The Attempt at a Solution



The main problem I am having is figuring out the change of the magnetic flux. I figured out the magnetic flux through the small coil at 14.4 x10^-6 WB (from the equation magnetic flux=BA cos theta) but I don't know what it changes to or from.
 
Physics news on Phys.org
Since the current in the solenoid is switched off, it no longer produces a magnetic field. So the flux changes to 0 over the course of 25 ms.
 
so for delta \Phi it would be (14.4x10^-6)-(0)?
 

Thread 'Errors and significant figures'

I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
View full post »
Thread 'Collision of a bullet on a rod-string system: query'

Thread 'Collision of a bullet on a rod-string system: query'

In this question, I have a question. I am NOT trying to solve it, but it is just a conceptual question. Consider the point on the rod, which connects the string and the rod. My question: just before and after the collision, is ANGULAR momentum CONSERVED about this point? Lets call the point which connects the string and rod as P. Why am I asking this? : it is clear from the scenario that the point of concern, which connects the string and the rod, moves in a circular path due to the string...
View full post »
Thread 'A cylinder connected to a hanging mass'

Thread 'A cylinder connected to a hanging mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

EMF induced by a magnet falling through a coil
Replies
4
Views
3K
Drop height of a magnet vs. induced EMF in a solenoid
Replies
41
Views
7K
Induced EMF in a coil outside a solenoid
Replies
15
Views
7K
EMF induced in a coil encircling an ideal solenoid
Replies
2
Views
2K
Why Does the Trigonometric Function in the FEM Calculation Differ?
Replies
3
Views
1K
Calculating Induced EMF in a Larger Solenoid Slipped Over Another Solenoid
Replies
5
Views
2K
Calculating Induced Current in a Coil Surrounding a Changing Current Solenoid
Replies
5
Views
4K
Calculating Magnetic Field Strength and Force of Eddy Currents in a Solenoid
Replies
49
Views
5K
EMF shielding using a conductor
Replies
6
Views
2K
Origin of repulsive force on a magnet approaching conducting ring?
Replies
5
Views
1K

Hot Threads

Recent Insights

Back
Top