Vikram Sarabhai Space Centre Technical Assistant Electronics & Communication Paper 2015

VSSC Technical Assistant/Scientific Assistant/Library Assistant exam is scheduled to be conducted on 30th July 2023 in Thiruvananthapuram. If you are the aspirants of the said exam, then you must read this question paper for practice.

1 The number 149 in octal code is
(a) 154
(b) 178
(c) 254
(d) 225
2 Universal gates are
(a) OR & AND gates
(b) NOR & NAND gates
(c) NOR & AND gates
(d) NAND & OR gates
3 In full adder, there are
(a) two binary number inputs and two outputs
(b) Three binary digit inputs and two binary outputs
(c) Three binary digit inputs and three binary digit outputs
(d) NAND & OR gates
4 The main advantage of PCM system is lower
(a) bandwidth
(b) power
(c) noise
(d) None of these
5 Automatic gain control is used
(a) To maintain the tuning correct
(b) To reduce the volume of loud passages of music
(c) To increase the amplification at high frequencies
(d) To maintain the same volume of output when stations of different strength are received
6 The rotor of an induction motor cannot run with synchronous speed because
(a) Lenz’s law will be violated
(b) Rotor torque will then be zero
(c) Induction motor would become synchronous motor
(d) Air function prevents it to do so
7 Using negative feedback for improvements, which statement is false
(a) Increased bandwidth
(b) Increased noise
(c) Decreased distortion
(d) High input impedance but lower output impedance
8 An amplifier has input impedance of 4 KOhm and output impedance of 80 kOhm. It is used in negative feedback circuit with 10% feedback. If open loop gain is 90, the closed loop input and output impedances are
(a) 40 KiloOhm and 8 KiloOhm repsectively.
(b) 4 KiloOhm and 80 KiloOhm repsectively.
(c) 0.4 KiloOhm and 800 KiloOhm repsectively.
(d) 8 KiloOhm and 160 KiloOhm repsectively.
9 In a current transformers
(a) the number of turns in primary and secondary windings are nearly equal
(b) the number of primary turns is very small as compared to number of secondary turns
(c) the number of secondary turns is very small as compared to the number of primary turns
(d) either (a) or (c)
10 The turn ratio of a transformer is 20 : 1, if a load of 10 Ohm is connected across the secondary, what will be the effective resistance seen looking into the Primary?
(a) 2 kOhms
(b) 4 kOhms
(c) 8 kOhms
(d) 32 kOhms