Elitmus.com a very helpful website that conduts exams and litmus paper to get tou PH score so that you become eligible for interviews at big companies which entertain you on the basis of you PH score.
I have given elitmus paper and have scored well around 90 percentile in my first attempt the website offers you to create an account and then you can see there which companies entertain litmus pH score for jobs.
So you get an idea about then accordingly you prepare for exams you can get all the syllabus from the websites.you need to select test centres online and have to pay the fee for exam there is no limit how many times you can give exam.
Once you give exam and you get score instantly then according to your score you can apply for company interviews on the websites this way the elitmus helps you to get better jobs and best companies.