Paper 7

1. An expression was given like B + A .B + !A .B + . . . . . and what will be the final
expression o/p :- ( Easy )

2. state diagram was given and what state will be detected ?

3. Counter and three states were given( 13 , 15 , 14 , 10 ) what will be the next value ? (
ans. 11 – Gray counter )

4. For one circuit inputs are ABCD and output is zero for first eight inputs and 1 for next
eight . What will be the expression for circuit ? ( ans :- A)

5. What is octal representation of 01010101 ? ( ans. 125 )

6. D flip-flop with inverted feedback was given and question was based on maximum
frequency allowed ( setup , hold etc. times were given )

7. Question based on instruction T states and CPI was asked .

8. What happens when HALT instruction is executed? ( Enter wait state and waits for
interrupt or reset , Enters in to sleep state , etc. ( ans. Waits for interrupt or reset )

9. What happens when PUSH instruction is executed : ( content of accumulator is saved,
content of PC is changed , stack pointer is decremented and value value is saved )

10. Two bulbs of 40 Watt and 60 Watts were added in series . What will happen ? ( 40 watt
will be brighter , 60 watts will be brighter , both will have same brightness , none ) ( Ans. 40 watt)

11. If widths of all PMOS an NMOS are doubled in any circuit then what will be effect on
noise margin ? ( ans. No effect)

12. If gate and one end of NMOS are connected to Vdd , what will be the output at second
end of NMOS ? ( Vdd- Vth – NMOS are bad 1 ‘s)

13. a band limited signal is sampled at Nyquist rate , to reconstruct it the output will be
given to : ( RC filter , Envelope detector , LPF with -- )

14. What is expression for Noise figure ?

15. always @ ( B or C)
if( B) D=C
Circuit will work as ( Mux, Tri state buffer , Latch , None ) ( Ans. --- Tri state
Buffer)