An ideal gas in a cubical box having sides of length l exerts a pressure p on the walls of the box. if all of this gas is put into a box having sides of length 4l without changing its temperature, the pressure it exerts on the walls of the larger box will be
a. 1/16 p
b. p
c. 1/64 p
d. 1/4 p

C).

Explanation:

As we know if temperature of the gas remains constant then

now we will have

P = initial pressure due to gas

initial volume of the gas is

now we know that side of the box is increased by 4 times

so new volume is

now we have

now we have

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 =