See this kind of practice sessions can be really helpful to increase your accuracy and time management. So its a good habit you are trying to adapt.

Now if you wish to practice Matrices and Determinants, then you can create a 2 hours practice session and you should try to complete 40 question atleast in this 2 hours. This will increase your speed and will create the actual examination required speed and accuracy. This target is applicable for both JEE MAINS & ADVANCED.

For more information regarding JEE MAINS preparation tips consider the link below:

https://engineering.careers360.com/articles/jee-main-preparation-tips

For more information regarding JEE ADVANCED consider the link below:

https://engineering.careers360.com/articles/jee-advanced-preparation-tips

I hope this helps. Wish you a great eve!