  # ISRO Scientist or Engineer Electronics 2010

Instructions

For the following questions answer them individually

Question 61

# The electric field measured in the far field of an antenna at a distance of 50m is 1 $$\frac{V}{m}$$. The average powerdensity at a distance of 500m from the antenna is Question 62

# A quarter wave monopole antennais situated above a perfectly conducting ground plane.It is driven by a 50V source at 500MHz through an internal impedance of 63.5Ω . The average powerradiated by the antennais Question 63

# Directional derivative of $$U = 2x^{3}y - 3y^{2}z$$ at P(1, 2, -1) in a direction towards Q(3, -1, 5) is Question 64

# Consider the equation Re(1/z)=c, where z is a complex number,c is a nonzero constant and Re( ) represents the real part. The equation describes a Question 65

# How many adders are required to realize a 256 point radix-2 FFT using decimation-in-time? Question 66

# A uniformly distributed randomsignal x[n] with mean $$m_{x} = 2$$ and variance $$\sigma_{x}^{2} = 3$$, is passed through a 3-point moving-averagefilter having an impulse response $$\left\{h[n]\right\}=\left\{\frac{1}{3},\frac{1}{3},\frac{1}{3}\right\}$$ What will be the mean andvariance of output? Question 67

# A sine waveis applied to a balanced modulator. The peak output envelope poweris 1000 times the minimum output envelope power. Estimate the carrier suppression indBc. Question 68

# Consider a single error correcting (7, 4) cyclic code with generator matrix $$g(x) = x^3 + x^{2} + 1$$. Whatwill be the transmitted data if received vector r is 1101101? Question 69

# Consider a Golay’s (23,12) codewith t bits of error correction capability. For what value of t will the codeexactly satisfy the Hamming bound ? Question 70

# The maximum range of a monostatic Radar is R. If a target having a Radar cross section of $$10m^{2}$$ exists at $$\frac{R}{2}$$ what should be the target cross-section at $$\frac{3R}{2}$$ to result in an equalsignal strength at the Radar? OR