Which of the following is/are the physical test(s) employed for the manufacture of paper? I. Mechanical and strength properties II. Surface properties III. Optical properties IV. Permeability to fluids Select the correct answer using the code given below.

Step-by-step solution

Physical testing of paper is essential to evaluate its quality and suitability for specific applications. The standard physical tests employed in the paper manufacturing industry include: I. Mechanical and strength properties: These tests measure tensile strength, tearing resistance, bursting strength, folding endurance, and stiffness. II. Surface properties: These tests evaluate smoothness, friction, and abrasion resistance, which are important for printing and handling. III. Optical properties: These tests determ