Equal but opposite charges Q are placed on the square plates of an airfilled parallel-plate capacitor. The plates are then pulled apart to twice their original separation, which is small compared to the dimensions of the plates.

Which of the following statements about this capacitor are true? (There may be more than one correct choice)

A) The energy stored in the capacitor has doubled.
B) The energy density in the capacitor has increased.
C) The electric field between the plates has increased.
D) The potential difference across the plates has doubled.
E) The capactiance has doubled.

Please explain why you chose that answer.

A) The energy stored in the capacitor has doubled.

D) The potential difference across the plates has doubled.

E) The capacitance has doubled.

Explanation:

According to the formulas, E = QV^2 and Capacitance = (epsilon) A/d

The potential difference between the plated has been doubled as the separations have been increased by two times. As the potential difference has been doubled, the energy stored in the capacitor has also been doubled. The overall capacitance will be increased by two times as the separation increases.

note: the given question is incomplete.

complete question is given below.

which is an example of kinetic energy?

a. the energy stored in ethanol  

b. a hockey puck sliding across the ice  

c. a compressed spring  

d. a ball sitting at the top of a ramp

solution: the kinetic energy is the energy posses by the virtue of the motion of the object.

in the given options, a, c and d are the example of potential energy because it is the energy posses by the virtue of the rest of the object. but option b has the kinetic energy as the object is in motion.

hence, a hockey puck sliding across the ice   is the apex example of kinetic energy.

so, the option (b) a hockey puck sliding across the ice   is the correct option.