I, neeraj kumar , sending the BEL question paper pattern and some questions , asked in the written test of BEL that was held on 13,may,2007.
there was 150 questions(30 questions from general awareness,reasoning and english) nd remaining questions frm technical
e.g. three ques based on the passage & english.
which element does nt belong to the above series.
(i) 259 (ii)729 (iii) 1000 (iv) 512. ans:(i)
some technical questions
(1)the breakdown voltage of a transitor with its base open is BV(ceo) and that with emitter open BV(cbo) then,
(2)a zener diode works on the principle of
ans:tunneling of charge carriers across the jn.
(3)under the high electric field,in a semiconductor with increasing electric field-
ans:the drift velocity of charge carriers saturate.
(4) built-in potential in a p-n jn.-
(i) is equal to the difference in the fermi level of the two sides,expressed in volts.
(ii) increased with increase in doping levels of the two sides.
(iii)increse with the increase in temp.
(iv)all the above.
ans : (iv)
(5) in an 8085,microprocessor system with memory mapped I/O:
(i) I/O device have 8-bit addresses.
(ii)I/O devices are accessed using IN and OUT instructions.
(iii)there can be a max of 256 input devices and 256 output devices.
(iv) airthmetic and logic operations can be directly performed with the I/Odata.
ans : (iv)
note: mostly quetions frm basic electronics,control systems and network systems