Why are force fields necessary to describe electric force? 0 A. Electric force acts at a distance. O B. Electric force can only attract objects. C. Electric force is a form of gravity. D. Electric force attracts two poles.

A. Electric force acts at a distance.

Explanation:

"Electric force," just like gravitational force is a "non-contact force." This means that even at a distance, two objects with no physical contact will create movement with the help of electric force. This leads to the concept of "force fields or field force" that explains why a charge object alters the region surrounding it. Once an object enters the region, it immediately experiences its force. An example of this is holding out one's hand near a "Van de Graaff generator." The electric force compels the hair strands to stand up.

5 w for 1hr = 5x60x60 joules=300x60=3000x6=18,000j as total energy conversion. efficiency of bulb needed for radiant to thermal within 18000