$($Looking for the step by step problem solving to get these answers$)$A physics student has a single$-$occupancy dorm room. The student has a small refrigerator

that runs with a current of $3\mathrm{.}00$A and a voltage of $110V,$ a lamp that contains a $100-W$ bulb,

an overhead light with a $60-$W bulb, and various other small devices adding up to $3\mathrm{.}00W.$

a$.$ Calculate the total current used by the student if all of the devices in their dorm

room are operated simultaneously. Answer: $4\mathrm{.}48A$

b$.$ Assume the power plant that supplies electricity to the dorm is $10km$ away and uses

a single $0-$gauge aluminum transmission cable with a diameter of $8\mathrm{.}252mm.$

Furthermore, initially we will ignore the complications of transformers and assume

that the current drawn by the dorm room is also the current on the transmission

cable. Calculate the voltage drop across the transmission cable and the minimum

voltage that the plant must deliver the electricity so that it is $110V$ at the dorm.

Hint: treat the transmission cables as cylinders and calculate the cable's resistance

from its length, diameter, and resistivity $($you can look up the resistivity in a table in

section $9\mathrm{.}3$ of the textbook$).$ Answers: $22V$ and $132V.$

c$.$ For the $132V$ transmission voltage you found in the previous part, calculate the

percentage of electrical power that is lost in transmission. Answer: $17\%$

d$.$ What would be the percentage of power lost if the power company used

transformers to deliver the electric power at $110kV?$ Hint: The transmission current

will be much smaller now and can be calculated using P$=$IV$.$ Answer: $0\mathrm{.}00002\%$