Define effective resistance of a number of resistors connected in a series or parallel combination

Derive an expression of affective resistance of four resistors connected in parallel.

Obtain an expression for equivalent resistance of two resistors connected in a series combination.

What happens to the effective resistance when two resistors are connected in series?

The equivalent resistance of two resistors connected in series is 6 Omega and their parallel equivalent resistance is 4/3 Omega . What are the values of resistances ?

Obtain an expression for equivalent resistance of two resistors connected in parallel.

a] Obtain an expression for the equivalent resistance of three resistors connected in series. Also write the expressions for current and voltage in the circuit. b] Mention any two advantages of connecting resistors in series.

Compare R_(s) with R_(p) for 'n' identical resistors connected in series and parallel combinations.