Final answer:
The dimension of the velocity gradient in Newton's law of viscosity is 1/s, representing the rate at which velocity changes per unit length in the MLT system.
Step-by-step explanation:
The dimension of the velocity gradient in the MLT system is 1/s (Option C). Newton's law of viscosity states that the shear stress between two layers of a fluid is directly proportional to the velocity gradient between them. Mathematically, this can be written as τ = μ(dv/dy). Here, τ represents the shear stress, μ is the coefficient of viscosity, v is the velocity, and y is the distance between the two layers of the fluid. The dimension of the velocity gradient, dv/dy, is 1/s (dimension of velocity/unit of distance).