- Magnetic flux refers to:
- The strength of a magnetic field
- The total number of field lines
- Whether an electromagnet is switched on or not.
- Whether the magnetism in a magnet is leaking away.

- The units for Flux density are
- Weber
- Weber per metre
- Weber per square metre.
- Weber per cubic metre

- A magnetic field of flux density 1.2 T acts on an area of rectangular cross-section 5.0 cm x 6.0 cm. What is the flux?
- 3.6 × 10
^{-3}Wb - 6.0 Wb
- 7.2 Wb
- 36 Wb

- 3.6 × 10
- The term "mu-nought", m
_{0}, is called:- The relative permittivity
- The permittivity of free space
- The relative permeability
- The permeability of free space

- A solenoid that has 200 turns is 4 cm long. A current of 3.0 amps flows through it. What is the flux density?
- 19 mT
- 0.19 mT
- 3.0 mT
- 1.5 mT

- A core of relative permittivity 200 is now placed in the solenoid in question 5. What is the flux density now?
- 0.30 T
- 0.38 T
- 3.8 T
- 6.0 T

- Which one of these gives the correct equation for the flux
*F*given out by an air-cored solenoid of length*l*, cross sectional area*A*m^{2}and*N*turns carrying a current*I*amp? - Which one of these gives the correct relationship for the the absolute permeability, m, of a magnetic material?
- The relative permeability of a material is found to be 0.9995643. Which statement is correct about this material?
- It is non-magnetic
- It is slightly magnetic.
- It is strongly magnetic.
- It is magnetically saturated.

- The flux density,
*B*, from a solenoid is measured against the current,*I*, and the data are plotted as a graph as shown.Two lines,

*A*and*B*are plotted. Which one of these is the correct conclusion from the experiment?- Line
*A*is a non-magnetic material, while line*B*is a magnetic material. - Line
*B*is a non-magnetic material, while line*A*shows that the magnetic material becomes magnetically saturated. - Line
*A*is a magnetic material and the flux density increases exponentially, while Line*B*is a magnetic material of a much lower relative permeability. - Line
*A*is a magnetic material, but is losing its magnetic properties as its temperature rises with the high current. Line*B*shows a magnetic material that is more resistant to high temperatures.

- Line