Gauss's law for magnetic fields says that magnetic flux is always zero. faraday's law says that a changing magnetic flux through a closed surface is equal to the induced electric field around that surface. but if magnetic flux is always zero, how can it ever change? explain in detail.

Explanation:

Gauss's law of magnetism is given as

here it is surface integral of magnetic field in a 3 Dimensional closed loop

So in this type of 3D closed loop number of linens of magnetic field is always zero because it always forms closed loops

Now as per Faraday's law

here we have to find the closed integral of 2 D planar loop of electric field which will be equal to potential difference

So this is non zero because total number of lines through a planar loop is not essentially zero.

the results is a decrease in air temperature with an increase of altitude.

explanation:

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 =