We are sometimes exposed to electric fields. To determine if
there is a risk of overload, there is a rule of thumb that prevents
sparks from switching if there is a field strength greater than 1kV
per mm, ie 1MV / m.
a) How big is the electrical field most between two conductors in a
230V wire (the peak voltage is 324V)? We assume that the distance
between the conductors is 2mm. Reply with a rounded integer. Answer
in [kV/m]
b) If a person arrives on a railway car, an accident may occur if
you get too close to the line. If the voltage is 16kV, at which
distance can a spark jump and kill a person? The regulations has
ruled that 270mm should be between conductors at this voltage. Then
you have warned against wire in humid air, etc. Reply with a
rounded integer. Answer in [mm]
c) If the insulation around a conductor to a coffee maker is
damaged, at which distance from the conductor can you get a spark
to switch to a sink? Answer with two decimals. Answer in [mm]
We are sometimes exposed to electric fields. To determine if there is a risk of overload,...
a) Estimate the voltage of a thundercloud from which lightning strikes theground 200m below. (Assume the ground is at 0v).b) An electric field intensity of 4 x 106 V/m isrequired to get a spark to form in air. If thevoltage applied across a spark plug is 5000V,What will be the spark gap between theelectrodes.(Please give your answer in mm).