Quick Summary Electromagnetic Induction PDF

## Based on the direction of the current it can be analysed whether the magnetic field is inward or outward. - The direction of the current is represented by 'I' and the direction of the magnetic field can be visualized by the direction of the magnetic field lines, represented by 'X' for inward and...

## Based on the direction of the current it can be analysed whether the magnetic field is inward or outward. - The direction of the current is represented by 'I' and the direction of the magnetic field can be visualized by the direction of the magnetic field lines, represented by 'X' for inward and '.' for outward. - The magnetic field is inward when the current flows clockwise and outward when the current flows counterclockwise. ## Derivation of Velocity = Electric field / Magnetic field - The magnetic field that produces magnetic force is provided by an electric force, hence $F_E = F_B$ - $F_B = qvB sin θ$ where $θ = 90°$ and $F_E = qE$ - $qUB = qE$ hence $UB = E... u=E/B$ ## Mass Spectrometer - The same concept applies to a mass spectrometer. - Centripetal force $F_c$ provides magnetic force hence $F_e = F_B$ - $mu^2/R = qvB$ hence $R = mu/qB$ ## Summary on Electromagnetism (Induction) - Faraday's Law: When a magnet is inserted into a wire loop an emf will be induced, which will act as a temporal source of energy. - Faradays law is all about induced emf: $ε = -dΦ_B/dt$. - This is negative because the emf acts opposite to the change in magnetic flux generating the emf (Lenz's law). ## Faraday's - Lenz Law: - $E = -dΦ_B/dt$ - When the number of loops is more than 1 then $emf = -NdΦ_B/dt$ - When the current 'i' in a circuit is constant then $di/dt = 0$ - $U_{AB} = Ldi/dt = 0$ - There is no change in the flux, - When current is increasing then $U_{AB} = Ldi/dt >0$ - According to Lenz’s law the emf induced by the current through the loop will act in the opposite direction to the flow of current if only the current is increasing. - When current is decreasing then $U_{AB} = Ldi/dt <0$ - The emf will act in the same direction as the current to maintain a steady current temporarily. ## Magnetic flux - When a magnet is moved into the loop, the direction of the magnetic flux is clockwise and the direction of the induced current is counterclockwise, which increases the magnetic flux. - When the magnet is pulled out of the loop, the direction of the magnetic flux is counterclockwise and the direction of the induced current is clockwise, which decreases the magnetic flux.