Which two, or more, of the following actions would increase the energy stored in a parallel plate capacitor when a constant potential difference is applied across the plates? 1. increase the area of the plates 2. decrease the area of the plates 3. increase the separation between the plates 4. decrease the separation between the plates 5. insert a dielectric between the plates

1. increase the area of the plates

4. decrease the separation between the plates

5. insert a dielectric between the plates

Explanation:

The energy of a capacitor is given by:

where is the capacitance and is the voltage or potential difference between the plates. With a constant potential difference, the energy is proportional to the capacitance i.e. the higher the capacitance, the higher the energy and vice-versa.

Now the capacitance has a geometric formula of:

where

is the permittivity of the material between the plates of the capacitor, is the area of the plates and is the separation distance between the plates.

From the relation, it is seen that the capacitance is directly proportional to the permittivity and the area but inversely proportional to the separation. In order to increase the capacitance, the permittivity or/and the area of the plates should be increased while the separation should be decreased.

0.19 m/s and 0.45 m/s

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

from wikipedia