A Zener diode, having breakdown voltage equal to 15 V, is used in a voltage regulator circuit shown in figure. The current through the diode is
A
5 mA
B
10 mA
C
15 mA
D
20 mA
2
AIPMT 2011 Mains
MCQ (Single Correct Answer)
+4
-1
In the following figure, the diodes which are forward biased, are
A
(A), (B) and (D)
B
(C) only
C
(C) and (A)
D
(B) and (D)
3
AIPMT 2011 Mains
MCQ (Single Correct Answer)
+4
-1
Pure Si at 500 K has equal number of electron (ne) and hole (nh) concentrations of 1.5 $$ \times $$ 1016 m$$-$$3. Doping by indium increases nh to 4.5 $$ \times $$ 1022 m$$-$$3. The doped semiconductor is of
A
p-type having electron concentration ne = 5 $$ \times $$ 109 m$$-$$3
B
n-type with electron concentration ne = 5 $$ \times $$ 1022 m$$-$$3
C
p-type with electron concentration ne = 2.5 $$ \times $$ 1010 m$$-$$3
D
n-type with electron concentration ne = 2.5 $$ \times $$ 1023 m$$-$$3
4
AIPMT 2011 Prelims
MCQ (Single Correct Answer)
+4
-1
Out of Syllabus
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
