If a document is to be produced using a duplicating camera, where should the camera be placed in or
der to obtain an exact copy? A. at the point which
is twice the focal lenght of the lens of the camera
B. at the optical centre of the lens of the camera C
between the principal and a point twice the foca
lens of the lens of the camera D. beyond a poin
twice the focal lenght of the lens of the camera​

Assume that two of the electrons at the negative terminal have attached themselves to a nearby neutral atom. there is now a negative ion with a charge -2e at this terminal. what are the electric potential and electric potential energy of the negative ion relative to the electron? the electric potential and the electric potential energy are both twice as much. the electric potential is twice as much and the electric potential energy is the same. the electric potential is the same and the electric potential energy is twice as much. the electric potential and the electric potential energy are both the same. the electric potential is the same and the electric potential energy is increased by the mass ratio of the oxygen ion to the electron. the electric potential is twice as much and the electric potential energy is increased by the mass ratio of the oxygen ion to the electron.