1. Current means flow of electrons and electrons are negative charged and so are attracted to the positive end of the battery and repelled by the negative end.

2. When battery is connected in a circuit that lets the electron flow through it, they flow from negative to positive.

3. When negative terminal of cell is connected to other negative terminal of the cell in a particular circuit then, current will not flow in circuit as electrons cannot flow from negative to negative terminal.

D should be the correct answer.

**Answer:**

a) dE={KdQdX}{r^{2} } *cosT

b) E = (2Q)/4eL^2)

**Explanation:**

a) The charge of element is:

dQ = Q/L

Where the y-axis elements will cancel, thus:

where dX is the length element = RdT and dT is the angle element, K = 1/(4pe)

b) The angle from x-axis is:

We integrate the expression from T to p/2 and multiply by 2:

Replacing the k value: