The most important thing is hardwork. When I say hardwork that doesn't mean anyone have to dig holes. Hardworking means to do study more and more upto the point when you find yourself absolutely confident that any question asked in exam, you will be able to answer it perfectly. I other words practice more and more questions and try to achieve perfection in your answers.
Other thing is smart work in which you have to plan, schedule your studies and timing smartly to finish things on time
Hope this things will be helpful.
Answer is option A
Explanation :- In regenerative braking, when brakes are applied, the back emf generated by the electric motor will be greater than original emf which will charge the battery while braking which would otherwise be wasted in conventional braking.
I can teach you various subjects of 12th std if you want and revise all your topics. As of advice I can tell you that please don't take any stress or tension. You have done hardwork so you will surely get results. Tension will hamper your progress and decrease your marks. Be confident and relaxed in last month.
Don't loose hope there is never too late to start again. You are feeling disinterested because you are not well prepared but keep in mind this is your life and exam is important for your future so keep working hard even if you don't enjoy it because at the end you will feel fantastic when you get good results.