A transistor is operated in common emitter configuration at VC = 2 V such that a change in the base current from 100 $$\mu $$A to 300 $$\mu $$A produces a change in the collector current from 10 mA to 20 mA. The current gain is
A
50
B
75
C
100
D
25
2
AIPMT 2011 Prelims
MCQ (Single Correct Answer)
+4
-1
If a small amount of antimony is added to germanium crystal
A
it becomes a p-type semiconductor
B
the antimony becomes an acceptor atom
C
there will be more free electrons than holes in the semiconductor
D
its resistance is increased
3
AIPMT 2010 Mains
MCQ (Single Correct Answer)
+4
-1
The following figure shows a logic gate circuit with two inputs A and B and the output Y. The voltage waveforms of A, B and Y are as given.
The logic gate is
A
NOR gate
B
OR gate
C
AND gate
D
NAND gate
4
AIPMT 2010 Mains
MCQ (Single Correct Answer)
+4
-1
Out of Syllabus
For transistor action
(1) Base, emitter and collector regions should have similar size and doping concentrations.
(2) The base region must be vety thin and lightly doped.
(3) The emitter-base junction is forward biased and base-collector junction is reverse biased.
(4) Both the emitter-base junction as well as the base-collector junction are forward biased.
Which one of the following pairs of statements is correct?
