Why should we connect electric appliances in parallel in a household circuit? What happens if they are connected in series?

How can you appreciate the role of a small fuse in house wiring circuit in preventing damage to various electrical appliances connected in the circuit?

If the resistance of your body is $100000 \mathrm{\Omega }$. What would be the current that flows in your body when you touch the terminals of a $12 \mathrm{V}$ battery?

Uniform wire of resistance $100 \mathrm{\Omega }$ is melted and recast into wire of length double that of the original. What would be the resistance of the new wire formed?

Imagine that you have three resistors of $30 \mathrm{\Omega }$  each. How many resultant resistances can be obtained by connecting these three in different ways? Draw the relevant diagrams.

Observe the circuit and answer the question given below.
Are resistors $3$ and $4$ in series?

Observe the circuit and answer the question given below.
Is the battery in series with any resistors?

What is the total emf in the circuit if the potential drop across resistor $1$ is $6 \mathrm{V}$?