Salam brother,
Glad to see that a lot of friends are motivated to go for physics.
well the length of the answers really matters,as it was a point of concern to me in my first attempt in CE 2010.However being an Electronics Engineer,I would suggest these tips.
a. Make your paper as much visual as possible,No body has stamina to read bulky and wordy questions.
b. Include Block diagrams( to indicate functional flow),equations( to explain the factors) ,graphs and tables (if applicable).
e.g For n type and p type : (for 20 Marks question ,3-4 pages enough)
1.
Defination( max 4 lines)
2.
Construction( 4 lines with diagram)
3.
Operation (1-2 page),this is the point where you have put your knowledge,but not in terms of words, include part b of the above.
4.
Applications( 5-6 points)
5.
Limitations( 4 points)
c. visualization of the paper highly increases the number of pages
.positively effecting the criteria of relevant approach and attention of the examiner.
d. I would recommend extreme use of pencil.