Why do we cover plug pinholes which are within the reach of children with cello tape or a plastic cover when not in use?

Why does the bulb in the circuit given below in figure does not glow? Draw the circuit with required change.

Paheli took a wire of length $10 \mathrm{cm}$. Boojho took a wire of $5 \mathrm{cm}$ of the same material and thickness. Both of them connected the wires as shown in the circuit given in figure. The current flowing in both the circuits is the same. Will the heat produced in both the cases be equal? Explain.

Paheli took a wire of length $10 \mathrm{cm}$. Boojho took a wire of $5 \mathrm{cm}$ of the same material and thickness. Both of them connected the wires as shown in the circuit given in the figure. The current flowing in both circuits is the same. Will, the heat produced be the same if the wires taken by them are of equal lengths but of different thickness? Explain.