  # ISRO Scientist or Engineer Electronics 2008

Instructions

For the following questions answer them individually

Question 71

# An amplifier has an input power of 2 microwatts. The powergain of the amplifier iis 60 dB. The output power will be Question 72

# A transmission line has a VSWR of2, the reflection coefficient is Question 73

# Which vacuum based deviceis widely used as a power amplifier in satellite communication systems? Question 74

# Maxwell’s equations establish the relationship between $$\overline{E}, \overline{D}, \overline{H}$$ and $$\overline{B}$$ at any point in a continuous medium. When we move from one medium to another, then which of the following statement is correct Question 75

# The input impedance of shortcircuited lossless line of length less than a quarter-wavelenth is Question 76

# The intrinsic impedanceof free space is 377 Ω. The approximate intrinsic impedance of a medium with relative premittivity and permeability of 4 and 1 respectively will be Question 77

# A 8 kHz communication channel has an SNR of 30 GB.If the channel bandwidth is doubled, keeping the signal power constant, the SNRfor the modified channel will be Question 78

# Two orthogonal signals $$s_1(t)$$ and $$s_2(t)$$ satisfy the following relation Question 79

# In which modulation system, when modulating frequency is doubled, the modulation index also becomes double. Question 80

# The matrix $$A = \begin{bmatrix}-4 & -3 & -3 \\1 & 0 & 1 \\ 4 & 4 & x \end{bmatrix}$$ is its own adjoint. The value of x will be OR