Analog and Digital Electronics - Online Test
Q1. A good current buffer has
Answer : Option B
Explaination / Solution:
No Explaination.
Q2. The following Karnaugh map represent a function F.
Which of the following circuits is a realization of the above function F?
Answer : Option D
Explaination / Solution:
No Explaination.
Q3. In the ac equivalent circuit shown in the figure, if iin is the input current and Rf is very larger, the type of feedback is
Answer : Option B
Explaination / Solution:
From the circuit, we observe that output is Vout (Voltage). Feedback is current
through resistance Rf , which is added to input current iin . Thus, the configuration
is voltage-current feedback.
Q4. The increasing order of speed of data access for the following devices is
i. Cache Memory
ii. CDROM
iii. Dynamic RAM
iv. Processor Registers
v. Magnetic Tape
Answer : Option B
Explaination / Solution:
No Explaination.
Q5. In the circuit shown, the op-amp has finite input impedance, infinite voltage
gain and zero input offset voltage. The output voltage Vout is
Answer : Option C
Explaination / Solution:
Given that the op-amp has infinite voltage gain, i.e.
AOL =
and zero input offset voltage
VIO = 0
So, we redraw the op-amp circuit as
Hence, the current I1 is drawn through resistance R2. So, the output voltage is
Vout = I1R2
Q6. The complete set of only those Logic Gates designated as Universal Gates is
Answer : Option C
Explaination / Solution:
No Explaination.
Q7. 
In the circuit shown below what is the output voltage (vout)if a silicon transistor Q and an ideal op-amp are used?
Answer : Option B
Explaination / Solution:
For the given ideal op-amp, negative terminal will be also ground (at zero voltage) and so, the collector terminal of the BJT will be at zero voltage.
i.e., VC = 0 volt
The current in 1 kΩ resistor is given by
This current will flow completely through the BJT since, no current will flow into the ideal op-amp (I/P resistance of ideal op-amp is infinity). So, for BJT we have
i.e.,the base collector junction is reverse biased (zero voltage) therefore, the collector current (IC ) can have a value only if base-emitter is forward biased.
Hence,
Q8. In an 8085 microprocessor, the contents of the Accumulator, after the following instructions are executed will become
XRA A
MVI B, F0H
SUB B
Answer : Option D
Explaination / Solution:
Q9. The circuit below implements a filter between the input current ii and the
output voltage v0. Assume that the opamp is ideal. The filter implemented is a
Answer : Option D
Explaination / Solution:
From diagram we can write 
Transfer function
Q10. X = and Y = are two 5-bit binary numbers represented in two’s complement format. The sum of X and Y represented in two’s complement format using 6 bits is
Answer : Option C
Explaination / Solution:
MSB of Y is 1, thus it is negative number and X is positive number
In signed two’s complements from 7 is
