DrDAQ is a versatile instrument that connects to the USB port of any PC. Using the supplied PicoScope software it can be used as an oscilloscope, spectrum analyzer and signal generator.
A filament lamp produced the following trace, with a frequency of 100 Hz.
A computer monitor gave the following frequency using the meter function:
The graphs below show how V (blue), I (purple) and P (yellow) vary with time.
The key point is that the power is always a positive quantity, and varies sinusoidally with a frequency = 2 x frequency of the mains voltage.
Care should be taken not to place the DrDAQ too close to a CRT TV screen as there is a possibility of damage due to a shock caused by the build-up of electrostatic charge on the screen.
The light-dependent resistor used as the sensor in this experiment does not respond rapidly to changes in light level, but it does produce a small change in resistance that can be used to record the change in light intensity.
Exmouth Community College.
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