Four copper wires of equal length are connected in series. thecross sectional areas are 1 cm2, 2 cm2, 3cm2, and 5 cm2. a voltage of 120 v is appliedto the arrangement. what is the voltage across the 2 cm2wire in units of volt?

a)15.5
b)11.8
c)19.7
d)59
e)29.5

Voltage across 2 cm² wire = 29.5 V

Explanation:

We equation for resistance,

Where ρ is resistivity, L is length and A is area.

Here for the four wires ρ and L is same, only area is different.

So we have

Here total voltage is given as 120 V,

In series connection voltage divides in the ratio of resistances

That is

Voltage across 2 cm² wire

Voltage across 2 cm² wire = 29.5 V

pecialized keyboards

it is given that trillions of microbes make up to 1% to 3% of the body mass.

let's take average of this percentage: 2%

consider the average mass of the human body as 70 kg.

then, trillions of microbes would have mass  

therefore, 100 trillion micro-organisms would weigh:

this is an approximate value and could change depending on the mass of the human body and percentage of the microbes present in it.

average mass per microorganism =