Question

The top of the atmosphere is about $400 \mathrm{kV}$ with respect to the surface of earth, corresponding to an electric field that decreases with altitude. Near the surface of the earth the field is about $100 \mathrm{V} \mathrm{m}^{-1}$, but still don’t get an electric shock, as we set out of our houses in to open because :(assume the house is free from electric field)
(A) Our body is a perfect insulator
(B) Our body and ground form an equipotential surface
(C) The original equipotential surfaces of open air remain same
(D) None of the above

Answer 1

Hint: We know that electric field is defined as the electric force per unit charge. The direction of the field is taken to be the direction of the force it would exert on a positive test charge. The electric field is radially outward from a positive charge and radially in toward a negative point charge. There are two types of electric fields: static or electrostatic fields and dynamic or time-varying fields. Electric fields have a definite magnitude and specific direction. The space around an electric charge in which its influence can be felt is known as the electric field. The electric field Intensity at a point is the force experienced by a unit positive charge placed at that point. Electric Field Intensity is a vector quantity. The magnitude and direction of the electric field are expressed by the value of E, called electric field strength or electric field intensity or simply the electric field. Using this theory, we have to solve this question.

Complete step by step answer
We know that dry atmosphere is not a conductor. Only when the top of the atmosphere increases to a very large value and there is moisture in the air, the lightning strikes the ground. Since 400kV is not very high voltage, it will not strive for the ground.
Since, our body and the surface of earth, both are conducting, therefore our body and the ground form an equipotential surface. As we step out into the open from our house, the original equipotential surfaces of open-air change, keeping our body and the ground at the same potential. That is why we do not get an electric shock.

Hence, we can say that the correct option is option B.

Note t should be known that nerves are tissue that offers very little resistance to the passage of an electric current. When nerves are affected by an electric shock, the consequences include pain, tingling, numbness, weakness or difficulty moving a limb. These effects may clear up with time or be permanent. Atmospheric electricity is always present, and during fine weather away from thunderstorms, the air above the surface of Earth is positively charged, while the Earth's surface charge is negative. Electricity is everywhere, even in the human body. Our cells are specialized to conduct electrical currents. Resting cells are negatively charged on the inside, while the outside environment is more positively charged. This is due to a slight imbalance between positive and negative ions inside and outside the cell.