A circular loop with a radius of 0.28 m is rotated by 90.0 degree over 0.150 s in a uniform magnetic field with B = 1.40 T. The plane of the loop is initially perpendicular to the field and is parallel to the field after the rotation. (a) What is the average induced emf In the loop?
(b) If the rotation is then reversed, what is the average induced emf in the loop?

correct it is c.) b b

answer: at 24 february, 2014 the population gets twice of its initial population.

explanation:

since we have given that

the population for alpha city, t years after january 1, 2004 is given as

first we find out the initial population, i.e. t=0,

so, our quadratic equation becomes,

according to question, we have said that if the population has twice its initial population, then it becomes

so, time taken to reach this above mentioned population is given by

now, we know that time can't be negative so, we take t=9.149 years.

hence, at 24 february, 2014 the population gets twice of its initial population.