Gap-fill exercise

Fill in all the gaps, then press "Check" to check your answers. Use the "Hint" button to get a free letter if an answer is giving you trouble. You can also click on the "[?]" button to get a clue. Note that you will lose points if you ask for hints or clues!

A is a device that allows current to flow in one direction only
A emitting diode - LED - requires less current than a bulb
An LDR is a -dependent resistor
Its changes under varying degrees of light