If in a p-n junction, a square input signal of 10 V is applied, as shown,
then the output across RL will be
A
B
C
D
Explanation
Here P-N junction diode rectifies half of
the ac wave i.e., acts as half wave rectifier. During
+ ve half cycle Diode is forward biased output across RL will be
During –ve half cycle Diode is reverse biased
output will not obtained.
2
AIPMT 2015 Cancelled Paper
MCQ (Single Correct Answer)
Which logic gate is represented by the following combination of logic gates ?
A
AND
B
NOR
C
OR
D
NAND
Explanation
The Boolean expression of this arrangement is
Y = $$\overline {\overline A + \overline B } $$ = $$\overline{\overline A} + \overline{\overline B} $$ = A.B
Thus, the combination represents AND gate.
3
AIPMT 2015
MCQ (Single Correct Answer)
In the given figure, a diode D is connected to an external resistance R = 100 $$\Omega $$ and an e.m.f. of 3.5 V. If the barrier potential developed across the diode is 0.5 V, the current in the citcuit will be
A
20 mA
B
35 mA
C
30 mA
D
40 mA
Explanation
Potential difference across resistance R
= 3.5 – 0.5 = 3.0 V
Current in circuit, I = V/R = 3/100 = 30 mA
4
AIPMT 2015
MCQ (Single Correct Answer)
The input signal given to a CE amplifier having a voltage gain of 150 is Vi = 2cos(15t + $${\pi \over 3}$$). The corresponding output signal will be