Question

$Pascalsecond$ has the dimension of

• A. Force
• B. Coefficient of viscosity
• C. Pressure
• D. Energy

Answer 1

The correct option is B Coefficient of viscosity

Pascal is a unit of pressure which is defined as force per unit area.

So Pascal Second would be same as the dimension of Force $\times$ Time/ Area, which is not having same dimension as force, pressure or energy (i.e. Force $\times$ distance).

The coefficient of viscosity is calculated by $\eta =\frac{Fr}{Av}$

where $F$ is the tangential force, $r$ is the distance between the layers, $A$ is area and $v$ is velocity.

Therefore it will have the same dimension as that of Force $\times$ (distance/speed) / Area i.e. Force/Area $\times$ (time) which is Pascal Second.