# ECE - Questions and solutions set-9

Electronics and communication Engineering Questions and solutions set-9
Question:-
Option (A)
PM signal
Option (B)
FM signal
Option (C)
PM and FM both
Option (D)
None of these
Correct Option:
B
Question Solution:
It is an FM signal, because the message signal is integrated to produce a phase variation of the carrier.
Question:-
Option (A)
4.13 dB
Option (B)
5 dB
Option (C)
6.98 dB
Option (D)
8.29 dB
Correct Option:
D
Question Solution:
T0=273 + 20 = 293° K
The effective noise temperature of the receiver
Te=(F - 1) T0
=(100.5 - 1) 293 ≈ 633° K
The overall effective noise temperature
TIN=Ta + Te
=1050 + 633 = 1683° K
Overall noise figure
F=
= = 6.74
F(dB)=10 log 6.74 = 8.29 dB.
Question:-
Option (A)
- 1
Option (B)
0
Option (C)
Option (D)
1
Correct Option:
D
Question Solution:
If all the elements of a determinant located on one side of principle diagonal are 0, then
Δ=Product of the diagonal elements
therefore, Δ = 1
Question:-
Option (A)
1
Option (B)
0
Option (C)
2
Option (D)
11
Correct Option:
A
Question Solution:
Since the eigen values of a real skew-symmetric matrix are purily imaginary or zero.
Letλ=bi(where i2 = -1)
= =
therefore, =