A circular loop of wire has its radius reduced in half in time Ät.A uniform magnetic field is at an angle of 60 ^$\degree$ to the plane of the coil,and the magnetic field doubles its intensity in the same time interval Ät.During this interval,what happens to the flux through the coil? A)It increases. B)It decreases. C)It remains the same. D)More information is needed to make this conclusion.

Question

Quizplus · Accepted Answer

The flux through a coil is given by the equation Φ = B*A*cosθ, where B is the magnetic field, A is the area of the coil, and θ is the angle between the magnetic field and the plane of the coil. As the radius of the coil is reduced by half, the area of the coil is reduced by a factor of 4. Therefore, the flux through the coil is reduced by a factor of 4. At the same time, the magnetic field doubles in intensity. Therefore, the overall flux through the coil is reduced by a factor of 2. Thus, the correct answer is B) It decreases.

A Circular Loop of Wire Has Its Radius Reduced in Half