Electric Generators and Faraday's Law

AI Thread Summary
When a generator operates at 60 Hz, it induces an EMF of 50 V. To determine the amplitude at 180 Hz, the angular frequency (ω) is calculated as 1131 m/s. The initial attempt to find the new EMF using the sine function led to a result of 64.3 V, which was incorrect. The correct approach involves using the formula ε0 = NABω, where NAB remains constant, leading to the expected answer of 150 V. The problem was resolved by correctly applying the relationship between frequency and induced EMF.
Violagirl
Messages
112
Reaction score
0

Homework Statement


When a generator turns at 60 Hz, the amplitude of the induced EMF is 50 V. What is its amplitude when it turns at 180 Hz if the magnetic field remains the same?

Homework Equations


ω = 2∏f

ε = ε0sin ωt


The Attempt at a Solution



If f = 180 Hz,

ω = 2∏(180 Hz)

ω = 1131 m/s

To find ε0 at 180 Hz:

ε/sin ωt = ε0

From this I get:

(50 V) / sin(1131 m/s)

ε0 = 64.3 V

However my book says that the answer should be 150 V and I'm not sure what I did wrong with it...
 
Physics news on Phys.org
50V is ε0.
ε0 = NABω. NAB doesn't change.

Solve for NAB and use that value to solve for the new ε0.
 
Thank you so much! Figured it out! :biggrin:
 

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 '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

Wave equation, wavelenght not given
Replies
6
Views
2K
Find the maximum amplitude of the induced EMF
Replies
9
Views
7K
Making sense of sequence of ideas in MIT OCW's 8.02 notes on Faraday
Replies
1
Views
1K
Faraday's Law - induced emf of a rotating loop
Replies
4
Views
11K
EMF and Peak Voltage of a Generator
Replies
2
Views
9K
Consistency of Faraday's Law and Electric Field Equation in Optics
Replies
2
Views
1K
How Does Inductance Affect Energy Storage in AC Circuits?
Replies
3
Views
6K
Understanding the math of definition of electromotive force
Replies
1
Views
941
Transverse Wave Velocity/Acceleration
Replies
10
Views
5K
Average power dissipation for induced current
Replies
2
Views
3K

Hot Threads

Recent Insights

Back
Top