ISRO Scientist/Engineer CS Solved Papers

Measurement of Hall coefficient enables the determination of :

Silicon is not suitable for fabrication of light emitting diodes because it is :

The band gap of elements arranged in ascending order is :

The following statements are made for NMOS & PMOS

1. The carrier mobility in NMOS is higher
2. PMOS require less area than NMOS
3. NMOS circuits are smaller than PMOS
4. PMOS are faster in switching.

Of these, the true statements are:

The following statements are made for FETS

1. In n-channel depletion mode MOS in the active region, the control voltage $V_{GS}$ is negative.
2. NMOS in depletion mode is cut off for $V_{GS}=0$
3. NMOS in enhance mode is cut off for $V_{GS}=0$
4. There is no path between source and drain in the enhancement mode

Of these, the true statements are:

Special handling precautions should be taken when working with MOS devices. The statement which is not true is :

If the input to the circuit of Figure is a sine wave, then the output will be:

A high gain OpAmp has $R_f = 10^5\;\Omega$ & $R_i = 10^3\;\Omega$. The correct statement is :

For various types of oscillators, the correct statement is:

For Butterworth & Chebyshev filters, the correct statement is :

In a feedback series regulator circuit, the output voltage is regulated by controlling the

In a fullwave rectifier circuit with centre tap transformer, if voltage between one end of secondary winding and centre tap is 300V peak, then PIV (peak inverse voltage) is

The rms value of the periodic waveform as shown in Figure is

The approximate equivalent resistance between terminals A and B for the following infinite ladder network comprising of 1 Ω & 2 Ω resistors is :

If the step response to the input step amplitude of 1 V is given by $V_o(t)=(1-e^{-t/RC})$, the network can be represented by :

For a parallel RC circuit as shown in figure, $R=20~\Omega$ & $C=0.9~\text{pF}$, which is to be matched to $50~\Omega$ over a bandwidth,

$$\int_{0}^{\infty} \ln\frac{1}{|\Gamma|} \, d\omega \le \frac{\pi}{R \cdot C}$$

The circuit has to be matched over 6 GHz to 18 GHz. What is the very best Γ that can be achieved:

In this circuit, V is a sinusoid input with freq f, current i contains:

The effect of phase error of local oscillator on spectral components in coherent detection of SSB Amplitude modulated signal is:

The maximum transmission power efficiency of DSB-C Amplitude Modulation is:

For identical total transmitted power, the ratio of $S/N$ for wide band FM to $S/N$ of DSB-AM (with $m_a=1$) is :
(Given $f_m = 15\text{ KHz}$ & frequency deviation $= \pm 75\text{ KHz}$)

A signal $m(t)=3\cos(6000\pi t)+4\cos(7000\pi t)+5\cos(10000\pi t)$ is to be sampled. What is the minimum sampling rate for band pass sampling for truthful representation :

Minimum number of bits required to represent maximum value of given analogue signal with 0.1% accuracy is :

An Ideal power limited communication channel with additive white Gaussian noise is having 4 KHz bandwidth and Signal to Noise ratio of 255. The channel capacity is :

An Ideal power limited communication channel with additive white Gaussian noise with 1 MHz bandwidth and Signal to Noise ratio of 15 is transmitting the information at theoretical maximum rate. If the Signal to Noise ratio is reduced to 7, how much bandwidth is required to maintain same rate :

Following constellation diagram represents :