This Is a Certified Answer

Certified answers contain reliable, trustworthy information vouched for by a hand-picked team of experts. Brainly has millions of high quality answers, all of them carefully moderated by our most trusted community members, but certified answers are the finest of the finest.
Head loss due to friction/unit length of pipe is proportional to mean velocity square V² and inversely proportional to diameter D of the pipe.

V = volumetric flow rate.. remains same

So head loss due to friction : ratio when flowing full / when flowing half full = 1

1 5 1