what is it ill know your question??!!
Answer:

Explanation:
From the question we are told that:
Diameter 1 
Diameter 2 
Generally the equation for Radius is mathematically given by
At Diameter 1

At Diameter 2

Generally the equation for continuity is mathematically given by

Therefore


Answer:
The most likely cause of a double precipitin ring in a RID test is when there is an antigen-antibody reaction ratio within the equivalence zone. The precipitin line forms when the antigen (with one or more epitopes) and antibody are in optimal proportions to each other and form an insoluble precipitates.
Answer: He should have ensured the following before beginning work;
1) All circuits must be de-energized before beginning work
2) All controls must be deactivated during work. LOTO(Log out tag out) must be practiced irrespective of the experience of the electrian or worker.
3) Technicians and Electrical workers must be instructed to know the unsafe conditions associated with their work.
Explanation:
We cannot assume that because he is experienced he cannot be prone to all this wrong practices. Humans tend to think that with experience people become less prone to errors and study has shown that this is not true. Safety must be a priority.