ISRO Scientist or Engineer Electronics May 2017

In Direct Broadcast System (DBS),

If analog sampling frequency of a band limited signal is doubled then corresponding digital sampling frequency will be

In communication system, if for a given rate of information transmission requires channel bandwidth, $$B_{1}$$ and signal-to-noise ratio $$SNR_{1}$$ If the channel bandwidth is doubled for same rate of information then new signal-to-noise ratio will be

Output SNR of a 10 bit PCM was found to be 30 dB, desired SNR is 42 dB. To achieve desired SNR by increasing the number of quantization levels, then new levels will be

Let Y(k) be the 5-point DFT of the sequence y(n) = {1 2 3 4 5}. What is the 5-point DFT of the sequence Y(k) ?

Let A be the series $$\sum_{n=1}^{\infty} \frac{(-1)^{n}}{\log(n+2)}$$ and B be the series $$\sum_{n=2}^{\infty} \left(\frac{3n-4}{3k+2}\right)^{\left(\frac{n+1}{3}\right)}$$ for real numbers. Then which of the following is true.

A test has 5 multiple-choice questions. Each question has 4 answer options (A, B, C, D). What is the probability that a student will choose “B” for at least three questions if
he/she leaves no questions blank?

The DTFT of a sequence x[n] is given by $$X(e^{j \omega})$$.since $$X(e^{j \omega})$$ is period function of $$\omega$$,it can be expressed classical Fourier series as $$X(e^{j \omega})= \sum_{n=-\infty}^\infty c_{n} e^{jn \omega_{o} \omega}$$ where $$\omega_{o}$$ is a fundamental frequency. Which of the following statement is correct?

Evaluate $$\int_{0}^{1}\frac{ \ln(x+1)}{x^{2}+1}$$

Fourier transform of a real and odd function is