You want to get an idea of the magnitude of magnetic fields produced by overhead powerlines. you estimate the that a transmission wire is about 11m above the ground. the local power company tells you that the lines operate at 240 kv and and provide a maximum power of 46 mw.
a. estimate the magnetic field you might experience walking under one such power line.
b. compare this field to the earth's field: bwire/bearth= ? %

a)

b) B=3.8%

Explanation:

The magnetic field can be find using the equation

a).

Now to determinate the current Io knowing the power and the voltage can determinate the current

Replacing

b).

The magnetic field of the earth is about 68uT so compare with this field

%

%

%=3.8 %

as a general rule, scissors have blades less than 6 in (15 cm) long and usually have handles with finger holes of the same size. shears have blades scissors used to cut hair or fabric must be much sharper.

their crystal patterns have been disrupted by stress