A current-carrying solenoid is 30 cm long and is wound with 1300 turns of wire.
ID: 1461064 • Letter: A
Question
A current-carrying solenoid is 30 cm long and is wound with 1300 turns of wire. It produces a magnetic field of 4.0×104 T at the solenoid's center.
How long would you make the solenoid in order to produce a field of 6.0×104 T at its center?
Express your answer using two significant figures.
Adjusting only the windings, what number would be needed to produce a field of 8.0×104 T at the center?
Express your answer using two significant figures
What current in the solenoid would be needed to produce a field of 9.0×104 T but in the opposite direction?
Express your answer using two significant figures.
Explanation / Answer
length of the solenoid l=30cm
no of turns N=1300
magnetic field B=4*10^-4 T
let current si i
B=uo*N*i/l
(4*10^-4)=(4pi*10^-7)*(1300)*(i)/(0.3)
====> i=73.46*10^-3 A
current B=73.46 mA
a)
B=uo*N*i/l
(6*10^-4)=(4pi*10^-7)*(1300)*(73.46*10^-3)/(l)
====> l=0.2 m
length l=20 cm
b)
B=uo*N*i/l
(8*10^-4)=(4pi*10^-7)*(N)*(73.46*10^-3)/(0.3)
no of turns N=2599.86
or
N=2600
c)
B=uo*N*i/l
(9*10^-4)=(4pi*10^-7)*(1300)*(i)/(0.3)
====> i=0.165 A
currnet i=0.165 A