Question

define parallel combination and series combination​

Answer 1

In series connection current through all the resistor are same or you can say every electron is moving in same direction but the voltage for each resistor are different. Parallel combination. In parallel connection ends of resistance are connected at same point.

Answer 2

A N S W E R :

$\underline{\mathcal{\red{SERIES\:\:COMBINATION\::}}}$

In this type of combination, the two or more resistances are connected end to end one behind the other.

Or

We can say that when several resistors are joined in series, the resistance of the combination Rs is equal the sum of their individual resistances,R1, R2, R3 & in thus greater than any individual resistance.

Formula create :

$\boxed{\sf{R_s = R_1+R_2+R_3 + ..............}}$

$\underline{\mathcal{\red{PARALLEL\:\:COMBINATION\::}}}$

In this type of combination, the two or more resistances are connected parallel to each other (example, not end to end, one behind the other).

Or

We can say that the reciprocal of the equivalent resistance of a group of resistances joined in parallel is equal to the sum of the reciprocals of the individual resistance.

Formula create :

$\boxed{\sf{\frac{1}{R_p} = \frac{1}{R_1} + \frac{1}{R_2} + \frac{1}{R_3} + ............... }}$