A square,clamping ammeter has four sides each with a length of 3.0 cm.The four sides of the ammeter are capable of measuring the magnetic field at the position of the sides.When the ammeter is clamped around a cylindrical wire carrying a 5.0 A DC current as shown in the figure,what is the average magnetic field measured in the sides of the clamp?
A)0.13 G
B)0.25 G
C)0.52 G
D)1.0 G
E)2.0 G

Question

A square,clamping ammeter has four sides each with a length of 3.0 cm.The four sides of the ammeter are capable of measuring the magnetic field at the position of the sides.When the ammeter is clamped around a cylindrical wire carrying a 5.0 A DC current as shown in the figure,what is the average magnetic field measured in the sides of the clamp? 
A)0.13 G 
B)0.25 G 
C)0.52 G 
D)1.0 G 
E)2.0 G

Quizplus · Accepted Answer

The magnetic field at the position of the sides of the ammeter can be calculated using the formula:
B = μ0 * I / (2 * r)

where B is the magnetic field, μ0 is the permeability of free space (4π x 10^-7 T·m/A), I is the current, and r is the distance between the wire and the side of the clamp.

Since the wire is cylindrical, the distance between the wire and each side of the clamp is 1.5 cm (half of the side length).

Therefore, the magnetic field measured in each side of the clamp is:
B = μ0 * I / (2 * r) = (4π x 10^-7) * 5.0 / (2 * 0.015) = 0.52 G

The average magnetic field measured in the sides of the clamp is simply the average of the four measurements, which is also 0.52 G. Therefore, the best choice is C.

A Square,clamping Ammeter Has Four Sides Each with a Length