In a series combination of resistors, the equivalent resistance is equal to:

The correct option is The sum of the individual resistances.

Explanation

In an electrical circuit, resistors can be arranged in series or parallel. In a series combination, resistors are connected end-to-end along a single path, meaning the same electric current flows through each resistor sequentially.

Analysis:

According to the laws of series combination of resistors:

• The total potential difference across the combination is the sum of the potential differences across each individual resistor ($V = V_1 + V_2 + \dots$).
• Using Ohm’s Law ($V = IR$), since the current ($I$) remains constant throughout the series circuit, the relationship is expressed as:
  $IR_{eq} = IR_1 + IR_2 + IR_3 + \dots$
  Dividing by $I$, we get:
  $R_{eq} = R_1 + R_2 + R_3 + \dots$

Thus, the equivalent resistance ($R_{eq}$) is the algebraic sum of the individual resistances. Consequently, the equivalent resistance in a series combination is always greater than the largest individual resistance in the circuit.

Comparison with other options:

• Less than the least individual resistance: "Less than the least individual resistance" is a characteristic of a parallel combination, not a series combination.
• The average of the individual resistances and The product of the individual resistances: These do not represent standard physical laws for resistor combinations.

Key Takeaway:

In a series circuit, the equivalent resistance is the sum of individual resistances ($R_{eq} = \sum R_i$), whereas in a parallel circuit, the reciprocal of the equivalent resistance is the sum of the reciprocals of individual resistances.