3B SCIENTIFIC PHYSICS 1009950 Manual De Instrucciones página 13

6.8 Diffraction

Clamp the cover plate (15) in the holder
on the hinge plate.

Set up the transmitter about 20 cm in front
of the plate.

Move the probe (21) in a horizontal plane
behind the plate.
Conclusion: even when the probe is in the
shadow of the plate, it can still pick up signals
due to diffraction.
6.9 Interference

Clamp the plate with the double slit (16)
centrally in the holder on the plate over
the hinge.

Position the transmitter about 12 cm in
front of the plate.

Move the receiver probe parallel to the
plate with the double slit about 6 cm be-
hind it.
Conclusion: Since the number of maxima is
larger than the number of slits, this demon-
strates the presence of interference.
6.10 Polarisation

Set up the polarisation grating (18) in the
screen holder.

Check the reception when the polarisa-
tion grating is aligned horizontally.

Check the reception when the polarisa-
tion grating is aligned vertically.
Conclusion: Since in one state a signal is re-
ceived but when the grating is rotated 90° no
signal reaches the receiver, it can be demon-
strated that the horn antenna produces a field
that oscillates in one direction only, i.e. the
output is polarised.
The experiment proves that the waves are
transverse.
If the transmitter and receiver are set up so
that one is vertical and one horizontal, no re-
ception is possible
If the polarisation grating introduced into the
beam and tilted by 45°, an attenuated signal
is received. The polarising plane is thus in-
clined.
6