Question

Which of the following scales are not linear in nature ?
(i) Decibel
(ii) Richter
(iii) Meter

• A. (i) only
• B. (ii) and (iii)
• C. (ii) only
• D. (i) and (ii)

Answer 1

The correct option is D (i) and (ii)

The answer is D.

The decibel (dB) is a logarithmic unit used to express the ratio between two values of a physical quantity, often power or intensity. One of these quantities is often a reference value, and in this case, the decibel can be used to express the absolute level of the physical quantity, as in the case of sound pressure. The number of decibels is ten times the logarithm to base 10 of the ratio of two power quantities, or of the ratio of the squares of two field amplitude quantities.
The Richter scale is not a linear scale. This means that an earthquake of magnitude 6 does not have twice as destructive power as the earthquake of magnitude 3. Actually, an earthquake with magnitude 5 is ten times more destructive than an earthquake of magnitude 4. The Richter scale is a logarithmic scale.
The Meter scale is a linear scale.
Hence, (i) and (ii) are non-linear scales.