Answer:
It is possible to statically charge objects by rubbing it against carpet fibers, but I'm not sure if that was in the article that you read.
Explanation:
Static charge can build up via carpet fibers.
Answer:
proportional to the current in the wire and inversely proportional to the distance from the wire.
Explanation:
The magnetic field produced by a long, straight current-carrying wire is given by:

where
is the vacuum permeability
I is the current intensity in the wire
r is the distance from the wire
From the formula, we notice that:
- The magnitude of the magnetic field is directly proportional to I, the current
- The magnitude of the magnetic field is inversely proportional to the distance from the wire, r
Therefore, correct option is
proportional to the current in the wire and inversely proportional to the distance from the wire.
Because the electromagnets can pick up magnetic material and move it around, hope this helps