Germanium, rectifier

Silicon, rectifier

Germanium, signal detector

Silicon, signal detector

Avalanche effect

Hall effect

Breakdown effect

Seeback effect

is minimum when load current is zero

is maximum when load current is zero

is always zero

remains constant irrespective of load current variations

passes low frequency signals

passes high frequency signals

passes signals between two frequency limits

rejects signals between two frequency limits

low-pass filter

high-pass filter

band-pass filter

band-stop filter