magnetic filed due to passing the current in straight wire Flashcards
EXPERIMENT on straghit wire
- Throw iron filling on a card- board surrounding straight wire carrying an electric current
- Knock the corner of the card- board slightly.
- Observation
The iron filling will arranged as Concentric circles
They are closer to each other near the wire, far away from each by increasing the distance from the wire
Ampere circular law
B = µ•I / 2π•d
factor which the magnetic flux density at the point depends and convert them to ratio rule
- The electric current intensity B & I a constant other factors
- The distance between the point and the center of the wire B& 1/d at constant other factor
- The magnetic permeability of the medium B&µ at constant other factor
Ratio
B1/B2 = µ1 / µ2 x I1 / I2 x d2/d1
detrmine the dirction of magnetic flux density by using
small compass
ampere right hand rule
what is the use of ampere right hand rule and how to use it
to detrmine the direction of the magnetic flux line around the straghit wire
- thump for durction of the current
- other finger for magnetic filed
It is advisable to live away from high voltage towers GR
- To the harmful effect of the magnetic filed of the electric current in the wires
- As the magnetic flux density decreases by increasing the distance from the wire B&1/d according to the relation B =miu •I / 2pay •d
Magnetic permeability of the medium
rule and unit
B x 2πd \ I
weber \ amp x m
the mark • reprecent ……………
the mark x represnbet ………….
out of the paper
in the paper
two straghit line same dirction
- the boint betweeen them Bt =
- the point out side the space between them Bt=
- between them ………… take place and why
atraction , repulsion
- B1 – B2
- B1 + B2
- atraction ,because the resultant magnetic flux bdensity in the space between the two wires ( Bt = B1 – B2 )
two straghit line oppiste dirction
- the boint betweeen them Bt =
- the point out side the space between them Bt=
- between them ………… take place and why
atraction , repulsion
- B1 + B2
- B1 – B2
- Repulsion , because the resultant magnetic flux bdensity in the space between the two wires ( Bt = B1 + B2 )
diff neutral point
it is the point where the total magnetic flux density vanishes so the magnetic neddle gives no deflection
what is the meaning of nutral point
the magnetic flux densityt will be cancelled by another on equel in magnitude and opposite in dirction
B1 = B2 oppiste dirction
the two wires in the same dirction
- the netrual point will be …….. the space between the two wires
between them out side
- the rule
- if I1 = I2
the two wires in the oppiste dirction
- the netrual point will be …….. the space between the two wires
between them out side
- the rule
- if I1 = I2
- between them
- I1 \ d1 =I2 \ X–d1
- so d1 = d2 the netural point will lie at midpoint
- out side
- I1 \ d1 =I2 \ X+ d1
- there is NO neutral point because d1 never equal d2
attraction takes place between two straight wires carrying electric current is placed nearer to each other if the current flow in same direction GR
because the resultant magnetic flux density i the space between the two wires [Bt = B1 + B2] is greater than that outside the two wires [Bt = B1–B2]
repulsion takes place between two straight wires carrying electric current is placed nearer to each other if the current flow in opposite direction GR
because the resultant magnetic flux density i the space between the two wires [Bt = B1 – B2] is greater than that outside the two wires [Bt = B1 + B2]
