In the energy band diagram of a material shown below, the open circles and filled circles denote holes and electrons respectively. The material is
A
an insulator
B
a metal
C
an n-type semiconductor
D
a p-type semiconductor.
2
AIPMT 2007
MCQ (Single Correct Answer)
+4
-1
For a cubic crystal structure which one of the following relations indicating the cell characteristics is correct ?
A
a $$ \ne $$ b $$ \ne $$ c and $$\alpha $$ = $$\beta $$ = $$\gamma $$ = 90o
B
a = b = c and $$\alpha $$ $$ \ne $$ $$\beta $$ $$ \ne $$ $$\gamma $$ = 90o
C
a = b = c and $$\alpha $$ = $$\beta $$ = $$\gamma $$ = 90o
D
a $$ \ne $$ b $$ \ne $$ c and ;$$\alpha $$ $$ \ne $$ $$\beta $$ $$ \ne $$ and $$\gamma $$ = 90o
3
AIPMT 2006
MCQ (Single Correct Answer)
+4
-1
The following figure shows a logic gate circuit with two inputs A and B and the output C.
The voltage waveforms of A, B and C are as shown below.
The logic circuit gate is
A
OR gate
B
AND gate
C
NAND gate
D
NOR gate
4
AIPMT 2006
MCQ (Single Correct Answer)
+4
-1
Out of Syllabus
A transistor is operated in common emitter configuration at constant collector voltage VC = 1.5 V such that a change in the base current from 100 $$\mu $$A to 150 $$\mu $$A profuces a change in the collector current from 5 mA to 10 mA. The current gain $$\beta $$ is
