Acoil of 40 turns is wrapped around a long solenoid of cross-sectional area 7.5×10−3m2. the solenoid is 0.50 m long and has 500 turns. (a) what is the mutual inductance of this system? (b) the outer coil is replaced by a coil of 40 turns whose radius is three times that of the solenoid. what is the mutual inductance of this configuration?

To solve this problem it is necessary to apply the concepts related to mutual inductance in a solenoid.

This definition is described in the following equation as,

Where,

permeability of free space

Number of turns in solenoid 1

Number of turns in solenoid 2

Cross sectional area of solenoid

l = Length of the solenoid

Part A )

Our values are given as,

Substituting,

PART B) Considering that many of the variables remain unchanged in the second solenoid, such as the increase in the radius or magnetic field, we can conclude that mutual inducantia will appear the same.

d) the number of neutrons plus the number of protons

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.