Four wires are made of the same highly resistive material, cut to the same length, and connected in series. wire 1 has resistance r1 and cross-sectional area a. wire 2 has resistance r2 and cross-sectional area 2a. wire 3 has resistance r3 and cross-sectional area 3a. wire 4 has resistance r4 and cross-sectional area 4a. a voltage v0 is applied across the series, as shown in the figure. find the voltage v2 across wire 2.give your answer in terms of v0, the voltage of the battery.

Explanation:

The 4 wires are connected in series: this means that the same current flow through them, and the voltage of the battery, V0, is equal to the sum of the voltages on each individual resistor:

Also, the equivalent resistance of the series circuit is

The voltage V2 across wire 2 is given by Ohm's law:

(1)

where I is the total current in the circuit, which is given by:

Substituting this into eq. (1), we find an expression for V2:

this means that the temperature of both substances will be equal

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.