A30-kva 8000/230-v distribution transformer has an impedance referred to the primary of 20 + j100 ω. the components of the excitation branch referred to the primary side are rc =100 kω and xm =20 kω (a) if the primary voltage is 7967 v and the load impedance is zl= 2.0 + j0.7 ω. what is the secondary voltage of the transformer? what is the voltage regulation of the transformer? (b) if the load is disconnected and a capacitor of –j3.0 ω is connected in its place, what is

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.

energy stored in the capacitor= 9.72 x 10⁻⁴ j

explanation:

the energy stored in the capacitor is given by

e= 1/2 c v²

e= energy stored

c= capacitance= 1.5 µc= 1.5 x 10⁻⁶f

v= potential difference=36 v

so energy stored= e= 1/2 (1.5 x 10⁻⁶) (36)²

energy stored= 9.72 x 10⁻⁴j