Calculating e.m.f Induced By Cycling Handlebars

  • Thread starter sara_87
  • Start date
  • Tags
    Induced
In summary, the conversation discusses a student cycling to college and the calculation of the e.m.f induced across the metal handlebars of the bicycle. It is explained that no current would flow through the student when touching the handlebars, even if the student is a good electrical conductor, due to the lack of changing flux through the loop. This is similar to connecting two batteries with equal voltage where no current flows. The student and handlebars have the same e.m.f, resulting in no current flow.
  • #1
sara_87
763
0

Homework Statement


An eager student cycles to college at 12 m/s. The metal handle bars are 60 cm wide and cut through the vertical component of the Earth’s magnetic field that has a flux density of 50 *10^(-6) T. Calculate the e.m.f induced across the handlebars. Explain why no current would flow through the student when he touched the metal parts of the handlebars even if he were a good electrical conductor.



The Attempt at a Solution


i can find the e.m.f:

e.m.f= -3.6 * 10^(-4)

but i can't explain why ...i think it has something to do with F=BIL


any help would be much appreciated
 
Physics news on Phys.org
  • #2
It is indeed because there is no changing flux through the loop of student+handlebars. But you can also ask yourself what e.m.f. is induced across the hands of the student.
 
  • #3
the emf that i calculated in the first part of the question?
 
  • #4
Yes, the student has the same e.m.f. as the handlebars. Does any current flow?
 
  • #5
i don't get it, i don't see how any of this is linked
 
  • #6
If you have two batteries with equal voltage and you connect their positive terminals together and the negative terminals together, how much current flows in the loop? It's the same problem.
 
  • #7
is it zero current?
 
  • #8
Yes. There's no e.m.f. difference between the two positive terminals or the two negative terminals. Do you see why your problem is the same?
 
  • #9
it's because the student and the handle bars have the same e.m.f...?
 
  • #10
Yes again.
 
  • #11
Oh thanks a lot i get it all now
 
Last edited:

1. What is e.m.f and how is it related to cycling handlebars?

Electromotive force (e.m.f) is the potential difference that is generated by a source of electrical energy, such as a battery. In the case of cycling handlebars, when the handlebars are rotated, a changing magnetic field is created which induces an e.m.f in the wires of the handlebar. This e.m.f can be used to power devices such as lights or electronic displays on the handlebars.

2. How is e.m.f induced in cycling handlebars?

E.m.f is induced in cycling handlebars through the principle of electromagnetic induction. When the handlebars are rotated, the magnetic field around the wires changes, which in turn creates an electric current and induces an e.m.f in the wires.

3. What factors affect the magnitude of e.m.f induced in cycling handlebars?

The magnitude of e.m.f induced in cycling handlebars can be affected by several factors, including the strength of the magnetic field, the speed at which the handlebars are rotated, and the number of turns in the wire. Additionally, the resistance and length of the wire can also impact the magnitude of the induced e.m.f.

4. How can e.m.f induced by cycling handlebars be calculated?

To calculate the e.m.f induced by cycling handlebars, the formula e.m.f = -N(dΦ/dt) can be used. N represents the number of turns in the wire, and (dΦ/dt) represents the rate of change of the magnetic flux through the wire. This formula can also be modified to take into account the resistance and length of the wire.

5. What are some practical applications of e.m.f induced by cycling handlebars?

The e.m.f induced by cycling handlebars can be used to power various devices on the handlebars, such as lights, GPS systems, or electronic displays. It can also be harnessed to charge batteries or power small electronic devices. In addition, the concept of e.m.f induction in cycling handlebars is also used in other technologies, such as dynamos on bicycles and generators in power plants.

Similar threads

Understanding Electromagnetic Induction: Flux and Induced e.m.f.
    • Introductory Physics Homework Help
Replies
1
Views
1K
"Barlow's wheel" used as an electrical generator
    • Electromagnetism
Replies
7
Views
1K
Inducing EMF by changing area
    • Introductory Physics Homework Help
Replies
3
Views
1K
How Do You Calculate Induced EMF in a Loop Near a Time-Varying Current?
    • Advanced Physics Homework Help
Replies
2
Views
5K
What is the induced magnetic force on this closed current loop?
    • Introductory Physics Homework Help
Replies
12
Views
203
A Image Method for B-Field Calculation on Iron Plate
    • Electromagnetism
Replies
2
Views
750
Can current be induced in a uniform magnetic field?
    • Electromagnetism
Replies
5
Views
5K
Faraday's law or Lorenzt force?
    • Electromagnetism
Replies
9
Views
2K
How Is Terminal Velocity Achieved by a Ring Falling Through a Magnetic Field?
    • Introductory Physics Homework Help
Replies
9
Views
2K
Explain how an e.m.f. is induced in the secondary coil
    • Introductory Physics Homework Help
Replies
5
Views
7K

Hot Threads

Recent Insights

Back
Top