Question

True or false
The magnetic field density or the magnetic flux is a measure of the strength of the magnetic field.

more emf is generated when a wire crosses more lines of magnetic flux in a shorter period of time.

High voltages for automobile sparkplugs are produced by static electricity.

microscopic eclectic current loops causes bar magnets to have a magnetic field.

Answer 1

first one..true
2nd: false.
.Faraday stated that an electromotive force (emf) is induced in a loop when the number of magnetic lines of force passing through the loop is changing. Actual number of lines passing through the loop does not matter; what is important is the rate at which the number changes. So the more lines the higher the EMF.

3rd: Spark plugs have an insulated central electrode which is connected by a heavily insulated wire to an ignition coil or magneto circuit on the outside, forming, with a grounded terminal on the base of the plug, a spark gap inside the cylinder.

for 4rth one read this site: http://hyperphysics.phy-astr.gsu.edu/hbase/electric/ohmmic.html...hope that helps..

Answer 2

http://hyperphysics.phy-astr.gsu.edu/hbase/electric/ohmmic.html

Answer 3

ist is true