Answer:
Electric field, E = 
Explanation:
Given that,
The potential difference across the membrane, 
The thickness of the membrane is, 
We need to find the magnitude of the electric field in the membrane. We know that the relation between electric field and electric potential is given by :
So, the magnitude of the electric field in the membrane is .
Answer:
B) Periodic Motion
Explanation:
When a pendulum is friction-less, i.e there are no damping forces acting on it, its motion will be periodic, i.e it will bob up and down going from potential energy to kinetic energy and back. Thus, the motion of the pendulum can be best described by the term "period motion", hence choice B.
If however, forces do act on the pendulum, and if they acts as to damp the pendulum, it will oscillate less and less as time goes by, and eventually come to a stop (in the real world this damping force is usually air resistance ). And if the force acts in such a way that it increases the oscillations, the pendulum will swing higher and higher, and the system will go haywire! :)
In the modern atomic model the number of electrons in a neutral atom is the same as the number of protons.
An atom contain, three fundamental particles, electron, proton, and neutron, neutron is charge less, there the charge of the atom is determined by the number of proton, and number of electron, Atoms are electrically neutral, it is only possible when number of electrons in an atom is equal to the number of proton.
