Deduce an expression for the effective resistance when number of resistors are connected (a) in series (b) Parallel

Deduce an expression for the internal resistance of the cell.

Deduce an expression for the effective capacitance when number of parallel plate capacitors are grouped in (a) series and (b) parallel.

Correct the sentences if required changing the underlined portion. To decrease the effective resistance the given resistors are to be connected in series.

Correct the sentences if required changing the underlined portion. To increase the effective resistance the given resistors are to be connected in parallel.

A conducting wire of resistance R is halved. Find the effective resistance when the two halves are joined in (a) series (b) parallel.