Answer to Question 1The most common type of receptacle is the duplex (double) receptacle.
Answer to Question 2ANS:Requirements
for wiring boxes as stated by the National Electrical Code are as follows:
The box must be fastened securely to the building.
The cable or conduit must be clamped securely to the box.
Cables running from box to box must run through the interior of the building's walls, floors, and
ceilings, be secured by staples or clamps near each box, and secured as needed to prevent the cable
from being accidentally caught and pulled.
The box must be grounded if it is metal. The ground wire from the cable is attached to the box by a
screw or by a grounding clip.
Wires in the box must be connected to each other by a special metal clamp or a solderless
connector.
Ground wires must be held together by a special metal clamp or a solderless connector.
Wires must be attached to terminals of switches and receptacles by tightening no more than one
wire under one screw or spring clip. If the receptacle or switch is equipped with special clamps,
one wire may be inserted into each clamp provided.
Positive or hot wires (black, red, or blue) must always be attached to brass-colored screws. Neutral
wires (white) must always be attached to aluminum screws. Ground wires (bare or green) are
attached to green screws.
When a white wire must be used as a positive wire (such as in a light switch), the insulation
showing in the box should be painted black or marked with black tape.
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