Q. For a laminar flow of fluid in a circular tube, 'h1' is the convective heat transfer co-efficient at velocity 'V1'. If the velocity is reduced by half and assuming the fluid properties are constant, the new convective heat transfer co-efficient is

• (A) 1.26 h1
• (B) 0.794 h1
• (C) 0.574 h1
• (D) 1.741 h1