@ xavier
As far as cbse board exams are concerned , they will ask u simple even numerical questions , donot worry about it .
frst of all u need to read the whole ncert twice , and solve the intext and exercise question from their ,
then move to ncert exempler , and solve question from their ,
then at the time of exam , do the last 6 years board paper , with full concentration , THEN I WILL ENSURE , U CAN GET ABOVE 95 ,
and for numerical follow the following steps
1- read question carefully (twice )
2- write down all the value given
3- remember all the associated formula to find out that unknown thing , for example
or finding power
we use ,, P=VI , P=ISQUARE R , P = VSQUARE /R
4- THEN SEE WHICH FORMULA SATISFY THE GIVEN DATA OF THE QUESTION . 5- then apply that formula and solve the question .
ALL THE BEST ..