11. Electromagnetic induction (AHL)

Question 1

 Electromagnetic induction =

Answer 1

the process where a changing magnetic field induces an EMF cross a conductor placed in the field.

Question 2

 Magnetic flux =

Answer 2

the number of field lines passing through a surface (measured in Webers (Wb)).

Question 3

 Magnetic flux linkage =

Answer 3

the total magnetic flux across a coil.

Question 4

 Faraday’s law =

Answer 4

the induced emf in a circuit is equal to the rate of change of magnetic flux linkage through the circuit.

Question 5

 Lenz’s law =

Answer 5

the direction of the induced current is such as to oppose the change that produced the current.

Question 6

 The rms value =

Answer 6

the dc current or voltage that would produce the same power output as a given AC supply

Question 7

 Capacitance =

Answer 7

the charge per unit voltage which the capacitor is capable of maintaining

Question 8

 Time constant =

Answer 8

the time taken for the capacitor to discharge to 0.37 (1/e) of its original charge.