Draw a schematic diagram of an electric circuit consisting of a battery of two cells each of $1.5\, V$,$5\, \Omega$,$10\, \Omega$ and $15\, \Omega$ resistors and a plug key,all connected in series.

An electric lamp of $100 \,\Omega$,a toaster of resistance $50 \,\Omega$,and a water filter of resistance $500 \,\Omega$ are connected in parallel to a $220 \,V$ source. What is the resistance of an electric iron connected to the same source that takes as much current as all three appliances,and what is the current through it?

What is the maximum resistance which can be made using five resistors each of $1/5 \ \Omega$ (in $\Omega$)?

What is the equivalent resistance of a circuit when three resistors of $5 \Omega$,$10 \Omega$,and $30 \Omega$ are connected in parallel (in $\Omega$)?

The $I-V$ graphs of two resistors,and their series combination,are shown below. Which one of these graphs represents the series combination of the other two? Give reasons for your answer.

What is the highest and lowest total resistance that can be secured by combinations of four coils of resistance $4 \,\Omega, 8 \,\Omega, 12 \,\Omega$ and $24 \,\Omega$?