Answer:
a human that walks on earth
Explanation:
Lose electrons because they have a negative charge.
Answer:
The electric field is
and the ditection is from outer to inner side of the membrane.
Explanation:
We know the electric field (
) is given by
, 'V' being the potential.
In 1-D, it can be written as

where 'd' is the separation of space in between the potential difference is created.
Given,
and the thickness of the cell membrane is
.
Therefore the created electric field through the cell membrane is

Answer:
Option D
Explanation:
The work done can be given by the mechanical energy used to do work, i.e., Kinetic energy and potential energy provided to do the work.
In all the cases, except option D, the energy provided to do the useful work is not zero and hence work done is not zero.
In option D, the box is being pulled with constant velocity, making the acceleration zero and thus Kinetic energy of the system is zero. Hence work done in this case is zero.