Table lamps in particular MUST have polarized plugs.
When a bulb burns out, you often don't know or care if the power is
switched off
before you change the bulb and most of us won't go to the trouble of
unplugging
the lamp when doing something as simple and 'safe' as just changing a bulb.
BUT - the next time you DO change a bulb, notice that the metal base of
the bulb
is exposed to your hand while it is still in contact with it's socket.
Can you guess which wire (neutral = wide blade or hot = narrow blade) is
required to be connected to the base of the bulb (as opposed to the tip
of the
bulb.)
Answer: a correctly wired lamp is requied to have the TIP = HOT = narrow
blade
of plug and the larger, exposed, base = NEUTRAL (close to ground) = WIDE
blade.
I remember the Wide = Neutral, narrow = Hot requirement by asking the
question:
If a child is going to stick a paper clip into a wall outlet (ouch!) which
opening would be safer. Make the more likely paper clip side the safe side.
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Chuck V. Britton Email:brit0500@spacelink.msfc.nasa.gov