Question

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3) What is the effect of time on the bacteriocidal ect of time on the bacteriocidal effects of UV? The effect of distance? 4) Why is direct exposure to UV light important? 5) How does sunscreen work to protect human skin from exposure to UV light? - 108 -

Answer 1

solution

Answer of all three question are explained in following image.

83 solution effect of time and distance of us light exposure an bacteria. experiment In bacteria are exposed to us light for 20 min at varsed distances like a feet to 18 feet Result - The reduction in viable count of Ecdi. 6 feet = 1188104 cell criable) I there is log & feet = 0.97 x 189 call reduction in bact- to feet = 0.83 4109 call erial population. upto 8 feet. so 12 feat = 0.364189 cell I this is a maximum distance a disinfection. Experiment I - bacteria exposed to unlight at a fixed distane of eight fect & time exposure is varred from 5 min to 40 min at increament of s mine each Result - 10 min - 8. 24109 criable cell canat reduced) is min - 2.64104 20 MIR - 3.58109 after so min marginal increase in bacterial machration. so 20-25 mix exposure is adequate fer bacterials disinfection

84) thy is direct exposure to ur light is important? - because if we are doing experiment of bacterial disinfection there is need to be direct exposure of ow.light to cells - if we give exposure directly then er light directly affects ar cells by affecting cells function and if we wed mixed medicin for cell then some part & as light is absabed to medium so we can not predict experimentals result of disinfection of bacterial cell. – so if all ligut is direetly exposed to cell then it will directly affect the gowth z cet DNA &5) Work of sunscreen to portect skin exposure to uv.? sunscreen has following property- - they act as bulletproof jacket for us. - they stops bigh enessy photos of us. Tights. to reach to dus skin calls - they contains organic sunscreen melecule that abserb wr.light. - I contains inorganic pigments that absorb scatter & reflect our light