Question

For the following statements, indicate whether the statement is true or false and explain in words your reasoning.

a) If I increase the number of moving charged particles per cubic meter in a conductor, I will have to increase the cross sectional area of the conductor to get the same amount of current for the same electric field in the conductor.

b) The change in magnetic flux in a closed loop induces an EMF that opposes the change in magnetic flux.

c) The magnetic force per unit length of two long, parallel, current-carrying conductors is repulsive if the currents are flowing in the opposite direction.

d) . The total magnetic flux through a closed surface is equal to μ0I enclosed

make sure to explain your reasoning

Answer 1

(a) that is false

current = n e V a

n= number of electrons per unit volume

e= charge of eletron

V= drift velocity and a= area of crossection

if we incease n,we will have to decrease the area of crossection to get the same current.

(b) part b is true. this is LENZ'S law that the induced emf opposes the change in magnetic flux .

(c)that is ture. two currnet carrying conductors having current in the opposite direction repel each other. that is because of the magnetic forces which are repulsive when current in the two parallel conductors is in opposite direction.

(d) this is false. the total magnetic flux through a closed surface is equal to zero.