transformer makes use of mutual induction for its operation in which change in magnetic field in one coil due to variation of current , induces voltage in the other coil. so changing magnetic field in the primary coil is very much needed for the transformer. Alternating current is a current which varies with time , hence it is suitable to produce changing magnetic field in the primary coil. on the other hand , the direct current remains constant all the time. hence can not produce a changing magnetic field. so DC current is not useful for transformers.
Answer:
Part a)
Part b)
Explanation:
As we know that magnetic flux through the loop is given as
now we have
now rate of change in flux is given as
now we know that
Now plug in all data
Part b)
Now the radius of the loop after t = 1 s
Now plug in data in above equation
