Two questions!

1. what is the purpose of the turbines in coal-fired power plants?
a) carrying electricity
b) burning coal
c) generating steam
d) converting energy

2. walt listed the steps that occur during the formation of natural gas.

plants and animals that live in a lake die.
the dead plants and animals sink to the bottom of the lake.
sand, dirt, and rocks bury the plants and animals.
the dead plants and animals are exposed to extreme heat and pressure.
within about twenty years, natural gas forms.

which best describes walt's mistake?
a)

The correct answer to the question is : 1) Converting energy and 2) Within about twenty years, natural gas forms.

EXPLANATION:

In coal fired power plants, the water is heated by burning coals. The heat produced in this process will convert water into steam. The steam is allowed to rotate the turbine. The turbine is attached to a generator which converts the kinetic energy of the steam into electric energy due to electromagnetic induction.

Hence, turbine helps in converting energy.

As per the second question, Walt listed the steps that occur during the formation of natural gas.

The natural gas is produced due to natural phenomenon. For this, millions of years are passed. So, it is a long range process in which the fossil of animals and planets buried beneath the surface are converted into natural gas under high pressure.

Hence, the mistake of Walt is  that the natural gas is produced withing twenty years.

force required to detach it is given by

charges are taken to be fundamental charge

now we have

so above is the minimum distance at which it will detach