Quiz Electronics Engineering 29 Aug 2020

Quiz Electronics Engineering
Exam: NIC
Topic: Miscellaneous
Date: 29/08/2020

Each Question carries 1 Mark
Negative Marking: 1/4
Time: 10 Minutes

Q1. Which one of the following statements about the 8085 is TRUE?
(a) only accumulator can be loaded with an 8-bit number in a single instruction
(b) The processor can be interrupted even after it executes HLT instruction.
(c) Program and Data Memories are different.
(d) When HOLD input is activated, the processor can execute register to register instructions.

Q2. The capacitance ‘C’ is equal
(a) C=ν/q
(b) C=q/ν
(c) q=c/ν
(d) q=ν/c

Q3. The distance between maxima and minima of a standing wave is
(a) λ/4
(b) λ/2
(c) λ
(d) 2 λ

Q4. The inverse Fourier Transform of 𝛿(f) is
(a) e^(-j2πt)
(b) u(t)
(c) 𝛿(t)
(d) 1

Q5. How many bits are required to encode 32 level PCM:
(a) 6
(b) 5
(c) 4
(d) 3

Q6. The unit of conductivity is
(a) ohm/m
(b) mho/m
(c) ohm. m
(d) mho. m

Q7. Consider Fourier representation of continuous and discrete-time systems. The complex exponential(i.e. signals), which arise in such representation, have
(a) same properties always
(b) different properties always
(c) non-specific properties
(d) mostly same properties

Q8. The address bus of 8085 is a group of:
(a) 8 lines
(b) 12 lines
(c) 16 lines
(d) 32 lines

Q9. The correct relationship between KVA and cos ϕ is
(a) (√k W)/cosϕ=KVA
(b) kW/cosϕ=KVA
(c) √(kW/cosϕ)=KVA
(d) None of the above

Q10. A 1 ms pulse can be converted into a 10 ms pulsed by using which one of the following?
(a) An astable multivibrator
(b) A J-K flip-flop
(c) A bistable multivibrator
(d) A monostable multivibrator

SOLUTIONS

S1. Ans.(d)
Sol.
Along with accumulator there are other general purpose or special registers which can store 8-bit data in a single instruction.
‘HLT’ means the execution of the program is completed. So, microprocessor can’t be interrupted after it executes HLT instruction.
When HOLD signal is ‘HIGH’ then microprocessor completes the machine cycle which was running and after its completion stops the use of data and address bus.
Program and data memories are same in 8085 microprocessor. Same memory space can be used for both purpose.

S2. Ans.(b)
Sol. Capacitance of a capacitor is defined as the ratio of the charge stored on the plates to the potential difference between the plates.
⇒ C=q/V

S3. Ans.(a)
Sol. Distance between two maxima or two minima is λ/2 and the distance between maxima and minima of a standing wave is λ/4.

S4. Ans.(d)
Sol. Fourier Transform of 1 is
1 ↔┴( F.T ) 𝛿(f)
1 ↔┴( F.T ) 2π𝛿(ω)

S5. Ans.(b)
Sol. Given:
Quantization level(L) = 32
We know that Quantization Level is
L = 2n where n is number of bits
Now,
L = 2n = 32 = 25
So, n = 5.
Therefore, number of bits = 5

S6. Ans.(b)
Sol. Conductivity=1/Resistivity=1/(ohm. m)
So, unit of conductivity = mho/m.

S7. Ans.(a)

S8. Ans.(c)
Sol. Features of 8085 microprocessor is –
8-bits data bus
16-bits address bus
NMOS technology
40 pins dual-in line package
clock frequency is 3 MHz.
clock cycle is 300 ns.
74 basic instructions and 246 opcodes

S9. Ans.(b)
Sol. Power factor is
cosϕ =KW/KVA

S10. Ans.(d)
Sol. A Monostable multi-vibrator is used as pulse stretcher. It is generally used to increase the width of a pulse or to produce a time delay within a circuit. The frequency of the output signal always remain same as that of the trigger pulse input, the only difference is in the pulse width.

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