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Physics
Physics
Problem
A student measures a magnetic field
B
1
B_1
B
1
at a distance
r
r
r
from a straight wire carrying current
I
I
I
. What is the ratio
B
2
B
1
\dfrac{B_2}{B_1}
B
1
B
2
if the current is doubled and the distance is tripled? a)
3
2
\dfrac{3}{2}
2
3
b)
2
9
\dfrac{2}{9}
9
2
c)
2
3
\dfrac{2}{3}
3
2
d)
4
3
\dfrac{4}{3}
3
4
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