What is the ratio of equivalent resistance of series combination of `n` equal resistance to the equivalent resistance in parallel combination of these `n` resistances ?

The equivalent resistance in series combination is

The equivalent resistance in series combination is :

The equivalent resistance of the parallel combination is:

Combination of resistance, equivalent resistance series and parallel combination.

Derive the formula of equivalent resistance of series combination of resistors.

Derive the formula of equivalent resistance of series combination of resistors.

The equivalent resistance of a series combination of two resistors is '9 Omega' and the equivalent resistance of a parallel combination of the same two resistors is 2 Omega . Find the resistances of the resistors.

The equivalent resistance of the combination across AB is .