A circuit element having terminals a and b has and Over a period of 20 seconds, how much charge moves through the element? If electrons carry the charge, which terminal do they enter? How much energy is transferred? Is it delivered to the element or taken from it?

Incomplete question

Complete question:A circuit element having terminals a and b has vab=10V and iba=2A. Over a period of 20 seonds, how much charge moves through the element? If electrons carry the charge, which terminal do they enter? How much energy is transferred? Is it delivered to the element or taken from it?

Answer: q (t) = 40C and w (t) = - 400j

The energy is delivered by the circuit element. The electrons through the terminal a

Explanation:

1. We were give the following data

V (t) = V (ab) = 10V, I (t) = I (a) = 2A

Current flows down terminal b toward a. Terminal a is positive reference while terminal b is negative reference.

2. The net charge which moves through the element over a period of t = 20s can be determined by the following equation.

q (t) = integral{ (20) - (0) }dt

= 2{20-0}

= 40C

3. The current (positive charge) flows from terminal b towards terminal a. Then the negative charge flows in opposite direction from terminal a towards terminal b. The electrons enter terminal a.

4. W (t) = integral { (20) - (0) }dt

= - 20integral { (20) - (0) }

= - 20 (20-0)

= - 400j

5. Energy is absorbed by an element when the positive charge moves from positive to negative reference. In pur case positive charge moves from negative reference b to positive reference a. Hence, energy is delivered by the circuit elements because of that transferred energy in previous case is a negative sign.