# Stroboscope

Objective

Observation of a periodic phenomenon with a periodic flashed light.

Procedure

- The disk is rotated by powering the motor by a 1.5 V cell.

- The disk is illuminated with light from the LED only, no other light should be present.

- Adjust the frequency of SQ1, the disk will appear stationary when it is equal to the frequency of rotation of the disk.

Discussion

When the frequency of the phenomenon under observation and the frequency of the flashing light are matching, one can see a still image.

What happens when the frequency of the light is slightly increased, or slightly decreased?

What happens when the frequency of the flasing light is twice the frequency of the phenomenon? and when it is the half of its value?