Both the answers from "Big D" and "N9KXF" are correct, but not complete. There is one aspect that needs to be remembered for AC power - the phase relationship between the voltage and current.

<span>For AC power, the more complete equation for power is P = V * I * cosx, where x is the phase angle between voltage and current. </span>

<span>If the phase angle between voltage and current is 90 degrees, then even though current may be flowing, the total power over a cycle would be zero. Reactive elements like inductors and capacitors have a 90degree phase relationship between voltage and current. They do not "dissipate" energy. They store energy and give it back during different parts of the AC cycle. </span>

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3 years ago

A point charge Q is placed at the center of a conducting spherical shell (inner radius a, outer radius b). What is the electric

sp2606 [1]

Answer:

a) $E=\dfrac{Q}{\varepsilon _o\times 4\pi r^2}\ N/C$

b)E=0

c) $E=\dfrac{Q}{\varepsilon _o\times 4\pi r^2}\ N/C$

Explanation:

Given that

A point charge Q is placed at the center of a conducting spherical shell .Due to this - Q charge will induce on the inner sphere surface and +Q will induce on the outer sphere surface .

a) r < a

At a radius r ,from gauss theorem

$E.ds=\dfrac{q_i}{\varepsilon _o}$