Page 12 - form 5 physics chapter 1

Diffraction Sound diffracting
of sound around corners so
allowing us to hear
others who are
speaking to us from
adjacent rooms.

Diffraction Light is diffracted if it
of light passes through a narrow
slit comparable in size to
its wavelength.
However, the effect is not
obvious as the size of the
slit increases. This is
because the wavelengths
of light are very short.

We can hear the sound Sound waves are more easily diffracted in
of a radio placed nearby comparison to light waves because the
a corner of a wall but we wavelength of sound waves is much longer than
cannot see the radio. the wavelength of light waves.
Why?

Procedure

¾ A ripple tank is filled with water and
set up as shown.

¾ Switch on the power pack.
¾ Use a barrier to block the incident

straight water waves. Observe the
wave pattern beyond the barrier.
¾ Send a straight water waves to pass
through a gap. Observe the pattern of
diffracted waves beyond the gap.
¾ Send straight water waves towards a
small gap. Observe the wave pattern
beyond the small gap.

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