Electronic Engineering MCQ Question Papers: ENTC, IT Interview Placement

Q1. The open loop gain of an amplifier is 50 but is likely to change by 20%. If negative feedback with  B= 0.1 is used, the change in gain will be about

a) 20%

b) 10%

c) 4%

d) 0.05%

Q2. Audio amplifiers need

a) Bass control

b) Treble control

c) both bass and treble control

d) Either bass or treble control

Q3. The open loop gain of an amplifier is 200. If negative feedback with B = 0.2 is used, the closed loop gain will be

a) 200

b) 40

c) 4.878

d) 1.212

Q4. In a tv, studio the function of vision switcher is to

a) edit television programs

b) Relay television programs

c) Control zoom lens

d) Mix audio and video signals

Q5. Y signal has maximum percentage of

a) Red colour

b) Blue colour

c) green colour

d) Red and blue colours

Q6. To ensure good transient response in audio systems the natural frequencies should be

a) Above 40 hz and below 15 khz

b) Above 40 hz

c) above 15 khz

d) Below 40 hz and above 15 khz

Q7. An am signal and a narrowband fm signal with identical carriers, modulating signals and modulation index of 0.1 are added together. The resultant signal can be closely approximated by

b) ssb with carrier

c) Dsb-sc

d) Ssb without carrier

Q8. The total number of channels allotted for cellular telephone is

a) 666

b) 333

c) 221

d) 111

Q9. In major diatonic musical scale, an octave is divided into

a) 12 intervals

b) 10 intervals

c) 7 intervals

d) 5 intervals

Q10. The bandwidth of dsb suppressed carrier modulation system when the modulating frequency varies between 500 hz and 5 khz is

a) 555 khz

b) 505 khz

c) 500 khz

d) 9 khz

Q11. The filter circuit for feeding a wooffer has

a) an inductance in series and capacitance in parallel

b) A capacitance in series and an inductance in parallel

c) A resistance in series and an inductance in parallel

d) An inductance in series and a resistance in parallel

Q12. The output resistance of a microphone is 20 ohms. It is to feed a line of impedance 320 ohms. To ensure maximum power transfer, the turn ratio of transformer is

a) 16

b) 256

c) 2

d) 4

Q13. Audio cassettes used in household tape recorders have a width of

a) 1″

b) 1/2″

c) 1/4″

d) 1/8″

Q14. The receiver of a pulsed radar can detect signal power in the order of

a) 1 w

b) 0.1 w

c) 10-5 w

d) 10-12 w

Q15. In a 100% amplitude modulated signal, the power in the upper sideband when carrier power is to be 100 w and modulation system ssbsc, is

a) 100 w

b) 66 w

c) 50 w

d) 25 w

Q16. Which camera tube has highest dark current?

a) plumbicon

b) Vidicon

c) Saticon

d) Gcd imager

Q17. If a sound wave has a frequency of 50 hz, the wavelength is

a) 66 m

b) 6.6 m

c) 0.66 m

d) 0.066 m

Q18. The dc voltage on plate modulated class c amplifier is 8 kv. If the peak modulating voltage is 4 kv, the peak rf voltage delivered to load is

a) 32 kv

b) 12 kv

c) 0.5 kv

d) 24 kv

Q19. In a vidicon camera tube

a) Grid g1 accelerates electrons

b) grid g2 accelerates electrons and grid g3, slows down electrons

c) Grid g3 accelerates electrons and grid g2 slows down electrons

d) Both grids g2 and g3 accelerate electrons

Q20. In a cd the sampling frequency is nearly

a) Half the highest frequency in audio signal

b) Equal to highest frequency in audio signal

c) double the highest frequency in audio signal

d) Four times the highest frequency in audio signal