Correct Answer - Option 4 : Between 351 - 450 N/m

^{2}
__Concept:__

Shear stress in the oil

\(τ = μ \times \frac {∂ V}{∂ y}\)

where: μ = Dynamic viscosity, τ = Shear stress, V = velocity of plate, y = distance between the plates.

__Calculation:__

__Given:__

Thickness = t = 1.2 cm = 0.012 m, μ = 15 poise = 1.5 Ns/m^{2}, ΔV = 3.25 m/s

\(τ = μ \times \frac {∂ V}{∂ y}\) \(τ = μ \times \frac {Δ V}{t}\)

\(τ = 1.5\times \frac {3.25}{0.012} = 406.25~N/m^2\)