You are given $10$ resistors each of resistance $2 \ \Omega$. First,they are connected to obtain the possible minimum resistance. Then,they are connected to obtain the possible maximum resistance. The ratio of maximum and minimum resistance is . . . . . . .

Two $10\,\Omega$ resistors are first connected in series and then in parallel. What is the ratio of the equivalent resistance in both cases?

The equivalent resistance of the given circuit between the terminals $A$ and $B$ is $....\Omega$

An electric kettle has two coils. When one of these is switched on,the water in the kettle boils in $6\,min$. When the other coil is switched on,the water boils in $3\,min$. If the two coils are connected in series,the time taken to boil the water in the kettle is ............. $min$.

$(a)$ Three resistors $1 \;\Omega, 2 \;\Omega$ and $3 \;\Omega$ are combined in series. What is the total resistance of the combination?
$(b)$ If the combination is connected to a battery of $emf \; 12 \; V$ and negligible internal resistance,obtain the potential drop across each resistor.

What is meant by parallel connection of resistors? Derive the equation for equivalent resistance in a parallel circuit.