3B SCIENTIFIC PHYSICS 1009950 Manual De Instrucciones página 12

6.5 Determining wavelength of standing
waves

Set up the transmitter and reflector plate
facing each other about 50 cm apart (an-
gle of incidence 0°).
The transmitted and reflected waves are su-
perimposed, resulting in a standing wave.

Using the microwave probe (21) (with the
marking on the special probe facing up-
wards) determine the distance a between
two adjacent minima (this corresponds to
half the wavelength).

Calculate the frequency f = c/ from the
wavelength  of the microwaves.


Results: a = 1,6 cm,
6.6 Refraction

Set up the basic configuration (5.1).

Insert the stand provided for the prism
(12) into the side facing away from the ar-
row.

Put the prism (13) onto the stand and line
it up.

Turn the long rail until the maximum re-
ception is attained.
Conclusion: microwaves penetrate paraffin.
As the waves pass from air to paraffin and
from paraffin to air, the speed of propagation
is altered and thus so is the direction (refrac-
tion).
6.7 Huygens' principle

Set up the transmitter (11) about 20 cm
from the plate holder and the receiver (19)
about 80 cm behind the late holder on the
rails.

Turn the receiver around on its rail so that
it is out of the bundled microwave beam
and the signal is clearly weakened.

Insert a single slit aperture into the plate
holder and secure it gently in place (line
up the centre of the slit in the centre of the
plate).
Conclusion: microwaves are diffracted by the
slit and wavelets can be detected beyond the
plate (the modulation signal is audibly
louder).
 9,4 GHz
5