Digital Circuits - Online Test
Q1. 
For the circuit shown in the figure, D has a transition from 0 to 1 after CLK changes from 1 to 0. Assume gate delays to be negligible. Which of the following statements is true
Answer : Option A
Explaination / Solution:
No Explaination.
Q2. 
In the following circuit, the comparators output is logic “1” if V1 > V2 and is logic "0" otherwise. The D/A conversion is done as per the relation
Volts, where b3 (MSB), b1,b2 and b0 (LSB) are the counter outputs. The counter starts from the clear state.
Volts, where b3 (MSB), b1,b2 and b0 (LSB) are the counter outputs. The counter starts from the clear state.The stable reading of the LED displays is
Answer : Option D
Explaination / Solution:
and when VADC = 6.5 V (at 1101), the output of AND is zero and the counter stops. The stable output of LED display is 13.
Q3.
In the following circuit, the comparators output is logic “1” if V1 > V2 and is logic "0" otherwise. The D/A conversion is done as per the relationVolts, where b3 (MSB), b1,b2 and b0 (LSB) are the counter outputs. The counter starts from the clear state.
Volts, where b3 (MSB), b1,b2 and b0 (LSB) are the counter outputs. The counter starts from the clear state.The magnitude of the error between VDAC and Vin at steady state in volts is
Answer : Option B
Explaination / Solution:
No Explaination.
Q4. Match the logic gates in Column A with their equivalents in Column B
Answer : Option D
Explaination / Solution:
Q5. 
For the output F to be 1 in the logic circuit shown, the input combination should be
Answer : Option C
Explaination / Solution:
Q6. In the circuit shown, the device connected Y5 can have address in the range
Answer : Option B
Explaination / Solution:
Q7. 
Assuming that the flip-flop are in reset condition initially, the count sequence observed at QA, in the circuit shown is
Answer : Option D
Explaination / Solution:
Q8. The Boolean function realized by the logic circuit shown is
Answer : Option D
Explaination / Solution:
Output of the MUX can be written as
Q9. In a microprocessor, the service routine for a certain interrupt starts from a fixed location of memory which cannot be externally set, but the interrupt can be delayed or rejected Such an interrupt is
Answer : Option D
Explaination / Solution:
Vectored interrupts : Vectored interrupts are those interrupts in which program control transferred to a fixed memory location.
Maskable interrupts : Maskable interrupts are those interrupts which can be rejected or delayed by microprocessor if it is performing some critical task.
Q10. 
For the 8085 assembly language program given below, the content of the accumulator after the execution of the program is
Answer : Option C
Explaination / Solution:
By executing instruction one by one
