Question

Which of the following pair has same dimensional formula?

• A. Tension and surface tension
• B. Year and light year
• C. Strain and angle
• D. None of these

Answer 1

The correct option is C Strain and angle

Tension and surface tension have different dimensional formulas as the tension is measured as force and surface tension is measured as force per unit length.

Year represents time and light year represents distance, thus they also have different dimensions.

Strain is defined as ratio of change in length (or area or volume) to the original length (or area or volume) and so it must be dimensionless.

Angle is nothing but ratio of arc length and radius which is also dimensionless.

Thus strain and angle both have the same dimensions which can be written as $\left[M^0{L}^0{T}^0\right]$.