# Analog Communication 2

Electronic Engineering MCQ Question Papers: ENTC, IT Interview Placement

Subject:  Analog Communication 2

Part 2: List for questions and answers of Analog Communication

Q1. Thermal noise is also known as

a) Johnson noise

b) Partition noise

c) Flicker noise

d) Solar noise

Q2. For a Unit ramp function area of pulse curve is unity

a) Discontinuous at time t=0

b) Starts at time t=0 and linearly increases with t

c) Both a and b

d) None of the above

Q3. In Unit impulse function

a) Pulse width is zero

b) Area of pulse curve is unity

c) Height of pulse goes to infinity

d) All of the above

Q4. Unit step function is

a) Exists only for positive side

b) Is zero for negative side

c) Discontinuous at time t=0

d) All of the above

Q5. Random signals is

a) May be specified in time

b) Occurrence is random

c) Repeat over a period

d) None of the above

Q6. An even function f(x) for all values of x and x holds

a) f(x) = f(-x)

b) f(x) = -f(x)

c) f(x) = f(x)f(-x)

d) None of the above

Q7. Properties of Hilbert transform are:

a) The signal and its Hilbert transform have same energy density spectrum

b) The signal and its Hilbert transform are mutually diagonal

c) Both a and b are correct

d) None of the above

Q8. Sine wave is a

a) Periodic signal

b) Aperiodic signal

c) Deterministic signal

d) Both a and c

Q9. A periodic signal is

a) May be represented by g(t) = g(t + T0)

b) Value may be determined at any point

c) Repeats itself at regular intervals

d) All of the above

Q10. At a room of 300K, calculate the thermal noise generated by two resistors of 10KO and 30 KO when the bandwidth is 10 KHz and the resistors are connected in parallel

a) 30.15 * 10^-3

b) 8.23 * 10^-23

c) 11.15 * 10^-7

d) 26.85 * 10^-7

Q11. At a room temperature of 293K, calculate the thermal noise generated by two resistors of 20KO and 30 KO when the bandwidth is 10 KHz and the resistors are connected in series

a) 300.66 * 10^-7

b) 284.48 * 10^-7

c) 684.51 * 10^-15

d) 106.22 * 10^-7

Q12. At a room temperature of 300K, calculate the thermal noise generated by two resistors of 10KO and 20 KO when the bandwidth is 10 KHz

a) 4.071 * 10^-6 V, 5.757 * 10^-6 V

b) 6.08 * 10^-6 V, 15.77 * 10^-6 V

c) 16.66 * 10^-6 V, 2.356 * 10^-6 V

d) 1.66 * 10^-6 V, 0.23 * 10^-6 V

Q13. Hilbert transform may be used in

a) Generation of SSB signals

b) Representation of band pass signals

c) Designing of minimum phase type filters

d) All of the above

Q14. Low frequency noise is

a) Transit time noise

b) Flicker noise

c) Shot noise

d) None of the above

Q15. Noise power at the resistor is affected by the value of the resistor as

a) Directly proportional to the value of the resistor

b) Inversely proportional to the value of the resistor

c) Unaffected by the value of the resistor

d) Becomes half as the resistance value is doubled

Q16. Noise is added to a signal in a communication system

a) At the receiving end

b) At transmitting antenna

c) In the channel

d) During regeneration of the information

Q17. Notch filter is a

a) Band pass filter

b) Band stop filter

c) Low pass filter

d) High pass filter

Q18. Noise voltage Vn and absolute temperature T are related as

a) Vn = 1/ v(4RKTB)

b) Vn = v(4RK)/ (TB)

c) Vn = v(4RKTB)

d) Vn = v(4KTB)/R

Q19. The noise temperature at a resistor depends upon

a) Resistance value

b) Noise power

c) Both a and b

d) None of the above

Q20. FM stands for

a) Frequent modulation

b) Frequency modulation

c) Frequency moderator

d) Frequent moderator

Part 2: List for questions and answers of Analog Communication