A space 2.5 cm wide between two large plane surfaces is filled with oil. Force required to drag a very thin plate of area 0.5 m2 just midway the surfaces at a speed of 0.5 m/sec is 1N. The coefficient of viscosity in kg–*/m2 is :
(A) 5 × 10–2
(B) 2.5 × 10–2
(C) 1 × 10–2
(D) 7.5 × 10–2
Correct option: (B) 2.5 × 10–2
Explanation:
Velocity gradient
as force on the plate due to viscocity is from upper as well as lower portion of the oil, equal from each part,
