Podcast Beta
Questions and Answers
What is the formula for magnetic flux when the magnetic field is uniform?
Which unit is NOT used to express magnetic flux?
What does the integral formula ΦB = ∫B.dA represent?
What is the dimension of magnetic flux?
Signup and view all the answers
What phenomenon describes the production of induced EMF in a closed circuit?
Signup and view all the answers
What is the condition for current to flow in a loop according to electromagnetic induction?
Signup and view all the answers
What does Faraday's Second Law state about induced emf?
Signup and view all the answers
Which of the following statements is true about induced current?
Signup and view all the answers
According to Faraday's First Law, what happens when magnetic flux through a closed circuit changes?
Signup and view all the answers
Which formula accurately represents Faraday's Law of electromagnetic induction?
Signup and view all the answers
Study Notes
Magnetic Flux
- The magnetic flux through any surface placed in a magnetic field is the total number of magnetic lines of force crossing this surface normally.
- If the magnetic field (B) is uniform, the magnetic flux (ΦB) is calculated by the product of the magnetic field strength (B) and the area of the surface (A): ΦB = B⋅A
- If the magnetic field is non-uniform, the magnetic flux is calculated through an integral: ΦB = ∫B⋅dA
- SI unit of magnetic flux is T⋅m² or Weber (Wb)
- CGS unit of magnetic flux: G⋅cm² or Maxwell (Mx)
- 1 Wb = 1 T⋅m² = 108 G⋅cm² = 108 Mx
- The dimensions of magnetic flux are [M T2 A−1]
Electromagnetic Induction
- Electromagnetic induction is the phenomenon of producing an induced electromotive force (EMF) and hence induced current due to a change of magnetic flux linked with a closed circuit.
- The current in a loop lasts as long as the flux is changing.
- Faraday’s Law states that whenever the magnetic flux linked with a closed circuit changes, an emf is induced in it, which lasts only as long as the change in flux is taking place.
- The magnitude of the induced emf is equal to the rate of change of magnetic flux linked with the closed circuit.
- The direction of the induced current opposes the change in magnetic flux (Lenz's Law).
Motional EMF
- The emf induced across the end of a conductor due to its motion in a magnetic field is called Motional emf.
- Motional Emf is directly proportional to the velocity, length of the conductor, and magnetic field strength.
- The induced current in a conductor moving in a magnetic field can be determined using Fleming's Right Hand Rule.
Fleming’s Right Hand Rule
- Stretch your thumb and the first two fingers of your right hand mutually perpendicular.
- If your forefinger points in the direction of the magnetic field, and your thumb points in the direction of motion of the conductor, then the central finger points to the direction of the current induced in the conductor.
Induced Charge
- Induced charge (ΔQ) is dependent on the net change in magnetic flux and not on the rate of change or time interval of the change in flux.
- The total induced charge in a closed loop is the induced emf divided by the total loop resistance.
Eddy Currents
- Eddy currents are circular currents induced in a conductor when the magnetic flux through the conductor changes.
- The eddy currents oppose the change in magnetic flux.
- Eddy currents are used in applications such as magnetic braking and induction heating.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Explore the concepts of magnetic flux and electromagnetic induction in this quiz. Understand the calculations and units involved, as well as Faraday's Law and its applications in circuits. Perfect for students delving into the fundamentals of electromagnetism.
