Calculating EMF in a Current Loop: 1000 Revolutions/Min with B = 0.45 T"

In summary, the group is discussing a problem involving a rectangular coil and its speed of rotation in a uniform magnetic field. The given dimensions of the coil are 75mm in width and 100mm in length. The question asks for the speed of rotation if an rms voltage of 0.25V is developed in a magnetic field of 0.45T in the z-direction. The correct answer is 1000 revolutions per minute. The conversation also includes a discussion on equations and the use of symbols, as well as the relevance of the coil's axis of rotation and the angle between the z-axis and the normal of the coil's plane.
  • #1
zerobladex
2
0
Hi all,

I have a certain problem I'm getting stuck on hopefully someone here can help

Homework Statement



A rectangular coil is 75 mm wide in the y-axis, 100mm long in the x-axis. What is the speed of the rotation if an rms voltage of 0,25 V is developed in the uniform field of B = 0.45 T in the Z direction.

The correct answer is supposed to be 1000 revolutions/min.

Homework Equations



emf = d[flux]/dt

*Sorry a little unsure of how to use the symbols and such

The Attempt at a Solution

:

I honestly am not sure where to start. Normally i would try to find the expression for magnetic flux, plug in the numbers and solve for the frequency, but it doesn't work so in this case.
 
Physics news on Phys.org
  • #2
Vpeak = (√2)·Vrms

The Peak Voltage is seen when dΦ/dt is maximum.

Does it matter whether the axis of rotation of the coil is along the x-axis or along the y-axis? No.

Suppose the loop is centered at the origin and the angle between the z-axis and the normal to the plane that the loop lies in is θ. Then the magnetic flux is ΦB=B·A·cos(θ).

dΦ/dt = ‒B·A·sin(θ)·(dθ/dt) .
 

FAQ: Calculating EMF in a Current Loop: 1000 Revolutions/Min with B = 0.45 T"

1. How do you calculate the EMF in a current loop?

The EMF (electromotive force) in a current loop can be calculated using the formula: EMF = -N * ΔΦ/Δt, where N is the number of turns in the loop, ΔΦ is the change in magnetic flux over time, and Δt is the time interval.

2. What is the significance of 1000 revolutions per minute in this calculation?

In this calculation, 1000 revolutions per minute refers to the rate at which the current loop is rotating. This information is important because it determines the value of Δt (time interval) in the EMF formula.

3. What is the value of B in this calculation?

In this calculation, B refers to the strength of the magnetic field in which the current loop is rotating. The value of B is given as 0.45 T (Tesla).

4. How does the number of turns in the loop affect the EMF?

The number of turns in the loop (N) directly affects the EMF, as shown in the EMF formula. Increasing the number of turns will result in a higher EMF, while decreasing the number of turns will result in a lower EMF.

5. Can this calculation be used for any current loop with different values?

Yes, the EMF calculation can be used for any current loop as long as the values of N, B, and the rate of rotation (Δt) are known. These values can vary for different current loops, but the same formula can be applied to calculate the EMF.

Similar threads

I Questions about cancelation of induced EMF and minimizing eddy currents
Replies
4
Views
1K
Calculating EMF for a Moving Loop Near a Wire with Current
Replies
10
Views
3K
Induced EMF in a moving Loop Conductor
Replies
3
Views
2K
Inductive charging: Emf induced in two coil loops
Replies
4
Views
2K
What EMF is induced in the loop at t=0?
Replies
6
Views
2K
How to Find Magnetic Flux and EMF in a Moving Loop Near a Current-Carrying Wire?
Replies
1
Views
1K
Magnitude of induced emf in current loop
Replies
1
Views
3K
How Do You Calculate Induced EMF in a Loop Near a Time-Varying Current?
Replies
2
Views
5K
Induced EMF and current in the circuit
Replies
10
Views
2K
EMF about a loop moving toward a wire with current
Replies
1
Views
2K

Hot Threads

Recent Insights

Back
Top