dear nupur 
1- elimination of options – this is most of the best known tricks . frst of all try to eliminate at least 2 options , so, that the probability will be high . 
2- trial and error method – in physics and some ques of physical chemistry , you need to check with every options , with the formula , and i can assure that 2 of them will be incorrect by analysing . so, try to do that 
3- rounding off the value = in physics and chemi while calculating try to take up the next value by rounding off , this way you can save the time . 
4- checking the units – in neet (phy ) , 3-5 questions are like this , the unit in the options are incorrect , then you can easily eliminate them . 
5- most probably maximum and minimum value cannot be the answer – in neet , its prooved that the maximum and minimum value in the options will not be the answer , but its not 100 percent sure always , so, try it at your own risk , if u dnt know anything abt the ques . 
HOPE IT CLEARS 
all the best 
regards 
kindly approve