Hi Kalpana,
Its helps to check your strength and weakness by looking through the topic wise question so that you can work on your weakness but problem with you is of time.
I think what you do is attempt practice
test via following method this my personal exprience hope it'll help you out:
1) Read the question once or twice and in a flash take a decide will take time to answer it?
2)if yes than mark the question(as the option is avaliable in both whizlab and exam) and move to next question and once you reaches last you can come back to those questions knowing how much time you have to spend on them.
3)if not than read as many times as you want but answer that question before proceding
Please give a test in this
pattern and let me know if it helped or not.