Question: 24: The reciprocal of resistance is :
(1) reactance
(2) mobility
(3) conductivity
(4) conductance
Answer: Option (4)
Explanation:
Resistance R is a measure of how much a material opposes the flow of electric current.
The reciprocal of resistance is called conductance, denoted by G.
Mathematically,
G = \frac{1}{R}where G is the conductance measured in siemens (S) and R is the resistance measured in ohms (Ω).
Other options:
– Reactance (X) is related to opposition to AC current due to inductance or capacitance.
– Mobility (\mu) is the drift velocity per unit electric field for charge carriers.
– Conductivity (\sigma) is the material property indicating how well a material conducts current, not the reciprocal of resistance directly.
Hence, the correct answer is conductance.