Question

a coil of one loop is made by a wire of length L and there after a coil of two loops is made by same wire. the ratio of magnetic field at the centre of coils respectively?

Answer 1

1

Answer 2

no ans is 1:4

Answer 3

twoo loops are placed closed to one another?

Answer 4

how are two loops placed relative to each other?

Answer 5

dunno -_-

Answer 6

ok the formula is uni.....u is meu nd n is coils per unit length nd i is current.........the rest depend on their relative arrangement

Answer 7

i guess for one loop
wire
2pi r = L
r=L/2pi
b=uoI 2pi r/4pi r^2
B=uo/2r
B=uo pi/L
B=uo pi/L.................................(1)
for 2 loop
4pi r= L
r=L/4pi
B=2 uoI/2r
B=4 uo pi/L.............................(2)
from the ratio of eqn 1 and 2 we get
1:4
hurrrah i did it thnx ^.^

Answer 8

B is proportional to current and inversely proportional to distance (radius).

Radius is halved and current is doubled, hence field will be four-fold.