A long wire is known to have a radius greater than 4.0 mm and to carry a current uniformly distributed over its cross section. If the magnitude of the magnetic field is 0.285 mT at a point 4.0 mm from the axis of the wire and 0.200 mT at a point 10 mm from the axis, what is the radius of the wire?
a. 4.6 mm
b. 7.1 mm
c. 5.3 mm
d. 12 mm
e. 10 mm
c
You might also like to view...
Suppose a star has twice the surface temperature of the sun and also twice the radius. How many times larger is the rate at which this star emits energy compared to the rate at which the sun emits energy?
A. It radiates at the same rate as the sun. B. 2 times C. 4 times D. 8 times E. 16 times F. 32 times T. 64 times
The magnetic field at a distance of 2 cm from a current carrying wire is 4 ?T. What is the magnetic field at a distance of 1 cm from the wire?
A) 2 ?T B) 4 ?T C) 6 ?T D) 8 ?T E) 10 ?T
A large spring requires a force of 130 N to compress it only 0.01 m. What is the spring constant of the spring?
a. 13 N/m b. 13 000 N/m c. 1.3 N/m d. 130 N/m e. 6 500 N/m
At what rate would the current in a 100-mH inductor have to change to induce an emf of 1000 V?
A) 100 A/s B) 1 A/s C) 1000 A/s D) 10,000 A/s E) 10 A/s