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
Report an error
The more specific you are, the faster it gets fixed. A source beats an opinion.
Prefer email? [email protected]
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.
Practise Electromagnetism
1,176 free Electromagnetism MCQs from Physics, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Discussion
Stuck on an option, or know a faster way to get there? Ask or explain it here.
No comments yet. Be the first to explain this one.
Exams that ask Physics questions like this
Physics is on 16 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
More Electromagnetism questions
The soft iron core is used in a transformer in order to:
The induced emf in a coil is proportional to:
A charge in uniform motion produces:
The torque in the coil can be increased by increasing:
A coil having number of turns N and cross-sectional area A is rotated in a uniform magnetic field B with an angular velocity ω. The maximum value of the emf induced in it is:
A point source of electromagnetic radiation has an average power output of 800W. The maximum value of electric field at a distance 3.5m from the source will be: