ISRO Scientist or Engineer Electronics 2006

ISRO Scientist or Engineer Electronics 2006 - Question 1

Report

The value of C which gives the critical damping in the given circuit is

A

2F

B

4F

C

8F

D

1F

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 2

Report

A series RLC circuit resonates at 3 MHz and has 3-dB bandwidth of 10 kHz. The Q of the circuit at resonance

A

30

B

$$\frac{300}{\sqrt{2}}$$

C

300

D

$$300\sqrt{2}$$

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 3

Report

The value of resistance R shown in the given figure is

A

3.5 Ω

B

2.5 Ω

C

1 Ω

D

4.5 Ω

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 4

Report

At 3-dB frequencies, current in the series RLC circuit equal current at resonance multiplied by

A

$$\frac{1}{2}$$

B

$$\frac{1}{\sqrt{2}}$$

C

$$\frac{1}{4}$$

D

$$\frac{1}{2\sqrt{2}}$$

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 5

Report

A series RLC circuit resonates at 1000 kHz. At frequency of 995 kHz, the circuit impedance is

A

Resistive

B

minimum

C

Inductive

D

capacitive

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 6

Report

If each stage had gain of 10dB and noise figure of 10dB, then the overall noise figure of two-stage cascade amplifier will be

A

10

B

1.09

C

1.0

D

10.9

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 7

Report

In Sigma-delta ADC, high bit accuracy is achieved by

A

Over sampling and noise shaping

B

Over sampling

C

Under sampling

D

None of the above

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 8

Report

Let s(t) denote the delta function. The value of the integral
$$\int_{-a}^{a}\delta(t) \cos \left(\frac{3t}{2}\right)dt$$ is

A

1

B

-1

C

0

D

$$\frac{\pi}{2}$$

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 9

Report

Consider the compound system shown in the above figure. Its output is equal to the input with a delay of two units. If the transfer function of the first system is given by $$H_1(Z) = \frac{Z - 0.5}{Z - 0.8}$$, then the

A

$$H_2(Z) = \frac{Z^{-2} - 0.2Z^{-3}}{1 - 0.4Z^{-1}}$$

B

$$H_2(Z) = \frac{Z^{-2} - 0.8Z^{-3}}{1 - 0.5Z^{-1}}$$

C

$$H_2(Z) = \frac{Z^{-1} - 0.2Z^{-3}}{1 - 0.4Z^{-1}}$$

D

$$H_2(Z) = \frac{Z^{-1} - 0.8Z^{-3}}{1 - 0.5Z^{-1}}$$

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 10

Report

The z-transform of the signal
$$x(n) = \begin{cases}1, & n = -1\\2, & n = 0 \\ -1, & n = 1 \\1, & n = 2 \\0, & otherwise \end{cases}$$

A

$$z + 2 - z^{-1} + z^{-2}$$

B

$$z^{-1} + 2 - z + z^2$$

C

$$z + 2z^2 - z^{-1} + z^{-2}$$

D

$$z + 2 - z^{+1} + z^{-2}$$

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 11

Report

For the circuit shown in the given figure, the voltage $$V_{AB}$$ is

A

6 V

B

10 V

C

25 V

D

40 V

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 12

Report

The equivalent Capacitance across 'ab' will be

A

$$0.2 \mu F$$

B

$$0.1 \mu F$$

C

$$0.5 \mu F$$

D

0

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 13

Report

The transfer function, $$T(s) = \frac{s}{s + a}$$ is that of a

A

Low-pass filter

B

Notch filter

C

High-pass filter

D

Band-pass filter

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 14

Report

A particular current is made up of two components: a 10 A dc and a sinusoidal current of peak value of 1.414 A. The average value of the resultant current is

A

Zero

B

24.14 A

C

10 A

D

14.14 A

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 15

Report

By doubling the sampling frequency

A

Quantisation noise decreases by 3dB

B

Quantisation noise density decreases by 3dB

C

Quantisation noise increases by 3dB

D

Quantisation noise density increases by 3dB

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 16

Report

The output voltage ($$v_o$$) of the circuit shown in the given figure is

A

Zero

B

5.7 V

C

6.9 V

D

12.6 V

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 17

Report

Assuming that only the X and Y logic inputs are available and their complements $$\overline{X}$$ and $$\overline{Y}$$ are not available, what is the minimum number of two-input NAND gates requires to implement $$X \oplus Y$$

A

2

B

3

C

4

D

5

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 18

Report

In the given network of AND and OR gates f can be written as:

A

$$X_0X_1X_2......X_n +X_1X_2......X_n + X_2X_3......X_n .......... X_n$$

B

$$X_0X_1 + X_2 + X_3 + ....... +X_{n - 1}.X_n$$

C

$$X_0 + X_1 + X_2 + ....... +X_n$$

D

$$X_0X_1X_3......X_{n - 1} +X_2 + X_3 + X_5......X_{n - 1} + ........ + X_{n - 2} + X_{n - 1} + X_{n}$$

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 19

Report

A Pulse train with a frequency of 1MHz is counted using a modulo 1024 ripple-counter built with J-K flip-flops. For proper operation of the counter the maximum permissible propagation delay per flip-flop stage is

A

100 n sec

B

50 n sec

C

20 n sec

D

10 n sec

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 20

Report

The A/D converter used in a digital voltmeter could be (1) successive approximation type (2) Flash converter type (3) Dual slope converter type. The correct sequence in the increasing order of their conversion times is

A

1, 2, 3

B

2, 1, 3

C

3, 2, 1

D

3, 1, 2

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 21

Report

The resolution of a DIA converteris approximately 0.4% ofits full-scale range. It is

A

An 8-bit converter

B

A 10-bit converter

C

A 12 bit converter

D

A 16 bit converter

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 22

Report

In a microprocessor, the resister which holds the address of the next instruction to be fetched is

A

Accumulator

B

Program counter

C

Stack pointer

D

Instructor register

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 23

Report

In microcomputer, WAIT States are used to

A

Make the processor wait during a DMA operation

B

Make the processor wait during a power interrupt processing

C

Make the processor wait during a power shutdown

D

Interface slow peripherals to the processor

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 24

Report

Which of the following statements are correct
1. A flip-flop is used to Store 1 bit of information
2. Race-around condition occurs in a J-K flip-flop when both the inputs are 1
3. Master-slave configuration is used in flip-flops to store 2 bits of information
4. A transparent latch consists of a D-type flip-flop

A

1, 2 and 3

B

1, 3 and 4

C

1, 2 and 4

D

2, 3 and 4

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 25

Report

How many 1 ‘s are present in the binary representation of
$$3 \times 512 + 7 \times 64 + 5 \times 8 + 3$$?

A

8

B

9

C

10

D

11

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 26

Report

For emitter-coupled logic, the Switching speedis very high because

A

Negative logic, is used

B

The transistors are not Saturated when conducting

C

Emitter-coupled transistors are used

D

Multi-emitter transistors are used

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 27

Report

The out put of the circuit shown below is

A

A pulse train of duration 0.5 sec.

B

A pulsetrain of duration 2 sec.

C

A pulse train of duration 1 Sec.

D

A pulsetrain of duration 5 sec.

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 28

Report

Gray code for number 7 is

A

1100

B

1001

C

0110

D

0100

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 29

Report

10 bit A/D converters, the quantization error is given by (in percent)

A

1

B

2

C

0.1

D

0.2

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 30

Report

For the switch circuit, taking open as 0 and closed as 1, the expression for the circuit Y.

A

$$A + (B + C)D$$

B

$$A + BC + D$$

C

$$A(BC + D)$$

D

None of these

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 31

Report

The Boolean expression for the shaded area in the Venn diagram is

A

$$\overline{x} + \overline{Y} + Z$$

B

$$X\overline{Y}Z + \overline{X}YZ$$

C

$$X + Y + Z$$

D

$$\overline{XY}Z + XY$$

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 32

Report

If the memory chip size is 256*1 bits, then the number of chips required to make up 1K bytes of memory is

A

32

B

24

C

12

D

8

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 33

Report

Given the decimal number — 19, an “eight bit two’s complement representation is given by

A

11101110

B

11101101

C

11101100

D

None of these

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 34

Report

The function shown in the figure when simplified will yield a result with

A

2 terms

B

4 terms

C

7 terms

D

16 terms

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 35

Report

The logic circuit given below converts a binary code $$Y_1Y_2Y_3$$ into

A

Excess -3 code

B

Gray code

C

BCD code

D

Hamming code

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 36

Report

A 4-bit Synchronous counter uses flip-flops with Propagation delay time of 25 ns each. The maximum possible time required for change of state will be

A

25 ns

B

50 ns

C

75 ns

D

100 ns

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 37

Report

An electromagnetic wave incident on a Perfect conductor is :

A

Entirely reflected

B

Fully transmitted

C

Partially transmitted

D

None of these

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 38

Report

The characteristic impedance of a lossless transmission line is given by

A

$$Z = \sqrt{LC}$$

B

$$Z = \sqrt{\frac{C}{L}}$$

C

$$Z = LC$$

D

$$Z = \sqrt{\frac{L}{C}}$$

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 39

Report

A lossless line of 50 ohms is terminated in a load of 100 ohms resistive. The VSWR is

A

1:2

B

2:1

C

4:1

D

1:4

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 40

Report

Which of the following does not exist in waveguides

A

TE waves

B

TM waves

C

TE waves and TM waves

D

TEM waves

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 41

Report

Two carriers of 2 GHz and 4 GHz respectively are frequency modulate by a signal of 10KHz, such that bandwith of the FM signal in the two cases are same. The peak deviation in the two cases are in the ratio of

A

1:8

B

1:2

C

2:1

D

1:1

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 42

Report

The bandwidth required for QPSK modulated channel is

A

Twice the BW of BPSK

B

Equal to BPSk

C

Equal to FSK

D

Half of the BW of BPSK

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 43

Report

Magic T is

A

Four part junction

B

Two part junction

C

Three part junction

D

It is not junction

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 44

Report

Diplexer is made of

A

Only receive filter

B

Only transmit filter

C

Only circulator

D

Both receive filter and transmit filter

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 45

Report

The gain G of an antenna of effective area A is given by

A

$$G = \frac{4 \pi \lambda}{A^2}$$

B

$$G = \frac{4 \pi A}{\lambda}$$

C

$$G = \frac{4 \pi A}{\lambda^2}$$

D

None

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 46

Report

If the short circuit and open circuit impedance ofa line are 5 and 20Ω respectively the characteristic impedanceis given by

A

100 Ω

B

10 Ω

C

15 Ω

D

10000 Ω

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 47

Report

The input impedance of short circuited line of length l where $$\frac{\lambda}{4} < l < \frac{\lambda}{2}$$, is

A

Capacitive

B

Inductive

C

Resistive

D

None of these

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 48

Report

Maximum coding gain in

A

Block Codes

B

Convolution Codes

C

Turbo Codes

D

RS Codes

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 49

Report

Noise figure of an amplifier depends on

A

Bandwidth

B

Output power

C

Power input

D

None of the above

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 50

Report

BCH code belongs to

A

Block Codes

B

Convolution Codes

C

Turbo Codes

D

None of the above

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 51

Report

When a carrier is phase modulated, with an integrated modulating signal, the resultant is

A

Phase modulated signal

B

Frequency modulated signal

C

Amplitude modulated Signal

D

QPSK modulated signal

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 52

Report

A satellite orbiting in 600 km orbit transmits 5 GHz frequency. The Doppler shift observed at the ground station, when the satellite is over head of the station is

A

Zero

B

Maximum

C

Infinity

D

None of the above

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 53

Report

A communication channel disturbed by additive white Gaussian noise has a bandwidth of 4kHz and SNR of 15. The highest transmission rate that such a channel can Support (in k-bits/sec) is

A

16

B

1.6

C

3.2

D

60

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 54

Report

A dual directional coupler is connected in a microwave reflectometer measurement setup. The reading of the power meter in the forward direction is 100 mW and in the reverse direction 4 mw. The VSWR is

A

4

B

0.4

C

1.5

D

10

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 55

Report

Linear amplifier with a gainof 30dB is fed with $$1.0 \mu W$$ power, the output power of the amplifier

A

1.0 W

B

0 dBm

C

30 dBm

D

-30 dBm

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 56

Report

10Watts RF Power is transmitted with a circular polarized antenna having gain of 4 0dB. A receiving antenna has vertical polarization The path loss is 100 dB. The receiving signal is

A

-83 dBW

B

-80 dBW

C

-86 dBW

D

+80 dBW

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 57

Report

$$\overrightarrow{P} = 2i - 3j, \overrightarrow{Q} = -3i + 4j - 2k$$, and $$\overrightarrow{R}$$ are in equilibrium, if $$\overrightarrow{R}$$ is

A

$$-i - j + 2k$$

B

$$i - j + 2k$$

C

$$i + j + 2k$$

D

$$i - j - 2k$$

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 58

Report

Arigid bodyis rotating with constant angular velocity $$\omega$$ about a fixed axis, if $$\nu$$ is the velocity of a point of the body, then curl $$\nu =$$

A

$$\omega$$

B

$$\omega^2$$

C

$$2 \omega$$

D

$$2 \omega^2$$

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 59

Report

Laplace transform of $$\sin^3 2t$$ is

A

$$\frac{24}{(s^2 + 4)(s^2 + 36)}$$

B

$$\frac{1}{(s^2 + 4)(s^2 + 64)}$$

C

$$\frac{48}{(s^2 + 4)(s^2 + 36)}$$

D

$$\frac{64}{(s^2 + 4)(s^2 + 36)}$$

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 60

Report

The value of the determinant

A

0

B

-1

C

1

D

2

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 61

Report

Solution of $$(D^2 + 4)y = \sin^2 x$$, is

A

$$y = A \cos 2x + B \sin 2x - \frac{1}{8} - \frac{x}{8} \sin 2x$$

B

$$y = A \cos 2x + B \sin 2x + \frac{1}{8} + \frac{x}{8} \sin 2x$$

C

$$y = A \cos 2x + B \sin 2x - \frac{1}{8} + \frac{x}{8} \sin 2x$$

D

$$y = A \cos 2x + B \sin 2x + \frac{1}{8} - \frac{x}{8} \sin 2x$$

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 62

Report

The value of k for which the lines $$2x + y - 1 = 0, 4x + 3y - 3 = 0$$ and $$3x + ky - 2 = 0$$, are concurrent is

A

-2

B

3

C

2

D

-3

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 63

Report

A box contains 5 black and 5 red balls. Two balls are-randomly picked one after another from the box, without replacement. The probability for both balls being red is

A

$$\frac{1}{90}$$

B

$$\frac{1}{5}$$

C

$$\frac{19}{90}$$

D

$$\frac{2}{9}$$

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 64

Report

$$x^3 + x \sin x$$ is

A

Constant function

B

Odd function

C

Even function

D

Periodic function

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 65

Report

$$\int \frac{dx}{x \sqrt{x^2 - a^2}}$$ is

A

$$\frac{1}{a} \cosec^{-1} \left(\frac{x}{a}\right)$$

B

$$\frac{1}{a} \sin^{-1} \left(\frac{x}{a}\right)$$

C

$$\frac{1}{a} \cos^{-1} \left(\frac{x}{a}\right)$$

D

$$\frac{1}{a} \sec^{-1} \left(\frac{x}{a}\right)$$

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 66

Report

Eigen values of $$\begin{bmatrix}-5 & 2 \\2 & -2 \end{bmatrix}$$ are

A

-6, -1

B

6, -1

C

-6, 1

D

6, 1

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 67

Report

The approximate equivalent resistance at the points $$X_1$$ and $$X_2$$ in the circuit shown below

A

60 Ω

B

40 Ω

C

80 Ω

D

20 Ω

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 68

Report

An inductor supplied with 50 V ac with a frequency of 10 kHz passes a current of 7.96 mA. The value of inductor is

A

1 mH

B

10 mH

C

100 mH

D

1 H

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 69

Report

Ina capacitor, the electric charge is stored in

A

Dielectric

B

Metal plates

C

Dielectric as well as metal plates

D

Neither dielectric nor metal plates

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 70

Report

Oscillator requires

A

No feedback

B

Negative feedback

C

Positive feedback

D

Either positive or negative feedback

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 71

Report

Which loss in a transformer varies significantly with load?

A

Hysteresis loss

B

Eddy current loss

C

Copper loss

D

Core loss

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 72

Report

The resistance of a parallel circuit consisting of two resistors is 12 Ω One of the resistance wires breaks and the effective resistance becomes 18Ω. The resistance of the broken wire is

A

48 Ω

B

18 Ω

C

36 Ω

D

24 Ω

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 73

Report

Time constant of a Series R-L circuit equals

A

$$\frac{L}{R}$$ second

B

$$LR$$ second

C

$$L^2R$$

D

$$LR^2$$

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 74

Report

A dc voltage V is applied at time t = 0 to a series RC circuit. The steady state current is

A

$$\frac{V}{R}$$

B

$$\frac{V}{C}$$

C

$$\frac{V}{\sqrt{R^2 + C^2}}$$

D

Zero

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 75

Report

The given circuit represents a

A

Low pass filter

B

High pass filter

C

Band pass filter

D

Band stop filter

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 76

Report

The very low frequency gain of the low pass filter shown in the given figure is

A

10 dB

B

20 dB

C

30 dB

D

40 dB

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 77

Report

The time-constant of the network Shown in the figure is

A

CR

B

2 CR

C

$$\frac{CR}{4}$$

D

$$\frac{CR}{2}$$

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 78

Report

For the circuit shown below the current l flowing through the circuit will be

A

$$\frac{1}{2}$$A

B

1 A

C

2 A

D

4 A

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 79

Report

When L is doubled and is halved, the resonance frequency of series tuned circuit becomes

A

Doubled

B

Halved

C

One quarter

D

Unchanged

View Solution

ISRO Scientist or Engineer Electronics 2006 - Question 80

Report

In a Series resonant circuit, with the increase in L

A

Resonant frequency will decrease

B

Bandwidth will decrease

C

Q will increase

D

All of these

View Solution