A uniform magnetic field B is directed out of the page. A metallic wire has the shape of a square frame and is placed in the field as shown. While the shape of the wire is steadily transformed into a circle in the same plane, the current in the frame:
Correct answer: A. Is directed clockwise
- A. Is directed clockwise
- B. Does not appear
- C. Is directed counterclockwise
- D. Is alternating
Explanation
Wire is same so Perimeter of square = Perimeter of circle4L = 2πRR = 2L/πArea of square = L2Area of circle = πR2 = π(2L/π)2= 4L2/π= 1.3 L2Area increases, flux increasesCurrent will counter fluxClockwise direction
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About Electromagnetism
Magnetic flux density and magnetic flux describe the strength of a magnetic field and the field passing through a surface. A charged particle moving through a magnetic field experiences a force perpendicular to its velocity and may follow circular or helical motion, depending on the angle between velocity and field.
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