To get an output Y= 1 in given circuit which of the following input will be correct ?
A
A $$ \to $$ 1, B $$ \to $$ 0, C $$ \to $$ 0
B
A $$ \to $$ 1, B $$ \to $$ 0, C $$ \to $$ 1
C
A $$ \to $$ 1, B $$ \to $$ 1, C $$ \to $$ 0
D
A $$ \to $$ 0, B $$ \to $$ 1, C $$ \to $$ 0
Explanation
The Boolen expression for the given
combination is
output Y = (A + B) · C
So it is clear that Y = 1,
when A = 1, B = 0 and C = 1
2
AIPMT 2012 Mains
MCQ (Single Correct Answer)
The input resistance of a silicon transistor is 100 $$\Omega $$. Base current is changed by 40 $$\mu $$A which results in a change in collector current by 2 mA. This transistor is used as a common emitter amplifier with a load resistance of 4 k$$\Omega $$. The voltage gain of the amplifier is
The figure shows a logic circuit with two inputs A and B and the output C. The voltage wave forms across A, B and C are as given. The logic circuit gate is
A
OR gate
B
NOR gate
C
AND gate
D
NAND gate
Explanation
The truth table is
The logic circuit is OR gate.
4
AIPMT 2012 Prelims
MCQ (Single Correct Answer)
Transfer characteristics [output voltage (V0) vs input voltage (Vi)] for a base biased transistor in CE configuration is as shown in the figure. For using transistor as a switch, it is used
A
in region III
B
both in region (I) and (III)
C
in region II
D
in region I
Explanation
In the given graph,
Region (I) – Cutoff region
Region (II) – Active region
Region (III) – Saturation region
Using transistor as a switch it is used in cutoff
region or saturation region.
Using transistor as a amplifier it is used in active
region.
Questions Asked from Semiconductor Electronics
On those following papers in MCQ (Single Correct Answer)
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