ENGINEERING KNOWLEDGE TEST (EKT)
ELECTRICAL AND ELECTRONICS STREAM
Q1. What is the next number in the series 1,3,11,19,37,_____
(a) 55 (b) 41 (c) 56 (d) None of the above
Q2. A car travelled 75% of way from town A to town B at an average speed of 50 mph. The car travelled
at the average speed of S mph for remaining part of the trip. The average speed for the entire trip
was 40 mph . What is S?
(a) 10 (b) 20 (c) 25 (d) 30
Soln : Using the formula average speed = total distance / total time
let the total distance be 100 kms
therefore average speed = 100 / [( 75/50) + (25/S)] = 40
solving we get S = 25 mph
Q3. If the area of the square is increased by 69% the side of the square increases by
(a) 13% (b) 30% (c) 39% (d) 130%
Soln : Suppose initial area was a2 now the new area is 1.69a2
as side of square is √area , therefore new side is √1.69a2 = 1.3a
therefore increase in side of square is = [(1.3a - a)/a]*100 = 30%
Q4. The value of Sin θ + Cosθ will be greatest when θ =
(a) 30 (b) 45 (c) 60 (d) 90
Soln : Greatest means maxima and for maxima differentiate wrt θ which gives
sinθ - cosθ = 0 => sinθ = cosθ Now only θ = 45 satisfies this
Q5. Out of the following pairs, choose the pair in which the physical quantities do not have identical
dimension?
(a) Pressure and Young's modules (b) Planck's constant and Angular momentum
(c) Impulse and moment of force (d) Force and rate of change of linear Momentum
Q6. Out of the following, which one is least commonly emitted by radioactive substance?
(a) electrons (b) electromagnetic radiations
(c) alpha particles (d) neutrons
Soln : proton and neutron are present in the nucleus .
Q7. Sound produced at a point is heard by a person after 5 seconds, while the same sound is heard by
another person after 6 seconds. If the speed of sound is 300 m/s, what could be the maximum and
minimum distances between the two persons?
(a) 1.8 km, 0.15 km (b) 2.2 km, 0.20 km
(c) 2.8 km, 0.25 km (d) 3.3 km, 0.30 km
Q8. The most electronegative element among the following is
(a) sodium (b) bromine (c) fluorine (d) oxygen
Q9. The nuclear particles which are assumed to hold the nucleons together are
(a) electrons (b) positrons (c) neutrons (d) mesons
Q10. The most abundant rare gas in the atmosphere is
(a) He (b) Ne (c) Ar (d) Xe
Q11. Quantizing noise occurs in
(a) PCM (b) Time - division - multiplexer
(c) FDM (d) PPM
Q12. Which of the following antennas is best excited from a waveguide?
(a) Biconical (b) Horn (c) Helical (d) Discone
Q13. The peak transmitted power in a radar system is increased by a factor of 16 the maximum range will
be increased by a factor of
(a) 2 (b) 4 (c) 8 (d) 16
Soln: Using the radar range equation ,
%5E2P_%7Bmin%7D%7D%5CBigr)%5E%7B%5Cfrac%7B1%7D%7B4%7D%7D)
if P't = 16Pt , ∴ R'max=(16)^1/4 => R'max = 2Rmax
Q14. The energy stored will be least in
(a) coil (b) capacitor
(c) resistor (d) same energy will be stored in all
Soln: Energy stored will be least in resistor as it is a dissipative element and dissipates all the energy instead to storing it while capacitor and inductor are energy storing elements .
Q15. Thevenin’s theorem is applied to networks with
(a) DC source only (b) AC source only
(c) both AC & DC source (d) none of the above
Soln: Thevenin's theorem is applicable for both AC and DC sources
Q16. The Shannon’s Theorem sets limit on the
(a) highest frequency that may be sent over channel
(b) maximum capacity of a channel with a given noise level
(c) maximum number coding levels in a channel
(d) maximum number of quantizing levels in a channel.
Q17. Maxwell’s electromagnetic equations are valid under all conditions except one that is
(a) they do not apply to non-isotropic media
(b) they do not apply to non-homogeneous media
(c) they do not apply to media which move with respect to system coordinates
(d) they do not apply to non-linear-media
Q18. Given a carrier frequency of 100 KHz and a modulating frequency of 5KHz, the bandwidth of AM
transmission is
(a) 5KHz (b) 200KHz
(c) 10KHz (d) 20KHz
Q19. In a modulation system, if modulating frequency is doubled, the modulation index also becomes
double, the system is
(a) FM (b) AM
(c) PM (d) both FM and AM
Q20. The bandwidth requirement of a telephone channel is
(a) 3KHz (b) 5KHz
(c) 10KHz (d) 15KHz
Q21. In class A operation of an amplifier the current flows through the active device for
(a) whole of the input cycle
(b) half of the input cycle
(c) more than half of the input cycle
(d) more than three fourth of the input cycle
Q22. P Type Semiconductor material as a whole is
(a) positively charged (b) negatively charged
(c) electrically neutral (d) dipole
Q23. Hartley oscillator is
(a) an inductively coupled oscillator
(b) capacitor coupled oscillator
(c) switchable for low frequencies
(d) resistance coupled oscillator
Q24. h parameters of a transistor
(a) are constant
(b) vary with temperature
(c) are dependant upon collector current
(d) none of the above
Q25. The target cross section is changing, the best system for accurate tracking is
(a) monopulse (b) conical scanning
(c) sequential locking (d) lobe switching
Q26. Waveguides are not used for frequencies below
(a) 1GHz (b) 10 GHz
(c) 100 Ghz (d) 500 Mhz
Q27. The unit of magnetic susceptibility is
(a) Wb-m^2 (b) Wb A-m
(c) Wb/A-m (d) Wb/m^2
Q28. Schmitt trigger can be used as a
(a) comparator (b) square wave generator
(c) flip flop (d) all of these
Q29. For making a capacitor, it is better to select a dielectric having
(a) high permittivity (b) low permittivity
(c) same permittivity as that of air (d) very low permittivity
Q30. The value of resistor creating thermal noise is doubled .the noise power generated is
(a) halved (b) doubled (c) unchanged (d) tripled
Soln: Thermal noise or white noise power = kTB
where kT = N0 = PSD of thermal noise
B = bandwidth
as can be seen from the formula thermal noise power is independent of resistor value .
Q31. Subtracting 0101 from 1110 in binary terms, we get
(a) 0110 (b) 1010 (c) 1001 (d) 0011
Q32. The universal gate is
(a) AND (b) NOR
(c) XOR (d) NAND
Q33. Fidelity in a communication receiver is provided by
(a) mixer stage (b) detector stage
(c) various amplifier section (d) audio stage
Soln: Fidelity is the ability of the receiver to reproduce all the audio frequencies at the output .
Q34. The TWT is sometimes preferred to the magnetron as a radar transmitter outputtube because it is
(a) capable of a longer duty cycle (b) a more efficient amplifier
(c) more broadband (d) less noisy
Q35. Modulation system used for video modulation in tv transmission is
(a) DSB (b) VSB
(c) SSB (d) SSBSC
Q36. A yagi antenna produces
(a) eight pattern (b) broadside pattern
(c) end fire array (d) helical pattern
Q37. Medium frequency waves travel mainly as
(a) sky waves (b) surface waves
(c) space waves (d) ground wave
Q38. In a two cavity klystron , the input cavity resonator is also known as
(a) velocity modulator (b) catcher cavity
(c) buncher cavity (d) accelerator
Q39. When the gate of a P- channel junction field effect transistor is more positive, the draincurrent
(a) is increased (b) is reduced
(c) remains unaltered (d) decreases
Q40. Multiplication of 2 binary numbers A and B yields 11011; if A is 101 B is
(a) 101 (b) 111
(c) 110 (d) none of these
Q41. Which of the following can measure pressure directly?
(a) LVDT (b) strain guage
(c) Rotameter tube (d) bourdon tube
Q42. The binary code of (21.125)10 is
(a) 10101.001 (b) 10100.001
(c) 10101.010 (d) 10100.111
Q43. An op-amp zero crossing detector is basically_______converter
(a) sine to square wave (b) square to sine wave
(c) sine to sine wave (d) sine to triangle wave
Q44. Which of the following is not a 8 bit microprocessor
(a) INTEL8085 (b) MOTOROLA6800
(c) ZILOG280 (d) FAIRCHILD9440
Q45. _________is used for keeping oscillator frequency away from any drift
(a) PLL (b) VCO
(c) comparator (d) frequency synthesizer
Q46. __________ is also an active filter
(a) RC filter (b) notch filter
(c) butterworth filter (d) band pass filter
Q47. In 8085 microprocessor ------is the highest priority interupt
(a) INTR (b) RST5.5
(c) RST (d) trap
Q48. In the standard TTL the totem pole stage refers to
(a) the multi emitter I/p stage (b) phase splitter
(c) o/p buffer (d) open collector o/p stage
Q49. Decimal equivalent of hex no E5 is
(a) 279 (b) 229
(c) 427 (d) 3000
Q50. Crossover distortion does not occur in __________ amplifiers.
(a) push-pull (b) class-A
(c) class-B (d) class-AB
ELECTRICAL AND ELECTRONICS STREAM
Q1. What is the next number in the series 1,3,11,19,37,_____
(a) 55 (b) 41 (c) 56 (d) None of the above
Q2. A car travelled 75% of way from town A to town B at an average speed of 50 mph. The car travelled
at the average speed of S mph for remaining part of the trip. The average speed for the entire trip
was 40 mph . What is S?
(a) 10 (b) 20 (c) 25 (d) 30
Soln : Using the formula average speed = total distance / total time
let the total distance be 100 kms
therefore average speed = 100 / [( 75/50) + (25/S)] = 40
solving we get S = 25 mph
Q3. If the area of the square is increased by 69% the side of the square increases by
(a) 13% (b) 30% (c) 39% (d) 130%
Soln : Suppose initial area was a2 now the new area is 1.69a2
as side of square is √area , therefore new side is √1.69a2 = 1.3a
therefore increase in side of square is = [(1.3a - a)/a]*100 = 30%
Q4. The value of Sin θ + Cosθ will be greatest when θ =
(a) 30 (b) 45 (c) 60 (d) 90
Soln : Greatest means maxima and for maxima differentiate wrt θ which gives
sinθ - cosθ = 0 => sinθ = cosθ Now only θ = 45 satisfies this
Q5. Out of the following pairs, choose the pair in which the physical quantities do not have identical
dimension?
(a) Pressure and Young's modules (b) Planck's constant and Angular momentum
(c) Impulse and moment of force (d) Force and rate of change of linear Momentum
Q6. Out of the following, which one is least commonly emitted by radioactive substance?
(a) electrons (b) electromagnetic radiations
(c) alpha particles (d) neutrons
Soln : proton and neutron are present in the nucleus .
Q7. Sound produced at a point is heard by a person after 5 seconds, while the same sound is heard by
another person after 6 seconds. If the speed of sound is 300 m/s, what could be the maximum and
minimum distances between the two persons?
(a) 1.8 km, 0.15 km (b) 2.2 km, 0.20 km
(c) 2.8 km, 0.25 km (d) 3.3 km, 0.30 km
Q8. The most electronegative element among the following is
(a) sodium (b) bromine (c) fluorine (d) oxygen
Q9. The nuclear particles which are assumed to hold the nucleons together are
(a) electrons (b) positrons (c) neutrons (d) mesons
Q10. The most abundant rare gas in the atmosphere is
(a) He (b) Ne (c) Ar (d) Xe
Q11. Quantizing noise occurs in
(a) PCM (b) Time - division - multiplexer
(c) FDM (d) PPM
Q12. Which of the following antennas is best excited from a waveguide?
(a) Biconical (b) Horn (c) Helical (d) Discone
Q13. The peak transmitted power in a radar system is increased by a factor of 16 the maximum range will
be increased by a factor of
(a) 2 (b) 4 (c) 8 (d) 16
Soln: Using the radar range equation ,
if P't = 16Pt , ∴ R'max=(16)^1/4 => R'max = 2Rmax
Q14. The energy stored will be least in
(a) coil (b) capacitor
(c) resistor (d) same energy will be stored in all
Soln: Energy stored will be least in resistor as it is a dissipative element and dissipates all the energy instead to storing it while capacitor and inductor are energy storing elements .
Q15. Thevenin’s theorem is applied to networks with
(a) DC source only (b) AC source only
(c) both AC & DC source (d) none of the above
Soln: Thevenin's theorem is applicable for both AC and DC sources
Q16. The Shannon’s Theorem sets limit on the
(a) highest frequency that may be sent over channel
(b) maximum capacity of a channel with a given noise level
(c) maximum number coding levels in a channel
(d) maximum number of quantizing levels in a channel.
Q17. Maxwell’s electromagnetic equations are valid under all conditions except one that is
(a) they do not apply to non-isotropic media
(b) they do not apply to non-homogeneous media
(c) they do not apply to media which move with respect to system coordinates
(d) they do not apply to non-linear-media
Q18. Given a carrier frequency of 100 KHz and a modulating frequency of 5KHz, the bandwidth of AM
transmission is
(a) 5KHz (b) 200KHz
(c) 10KHz (d) 20KHz
Q19. In a modulation system, if modulating frequency is doubled, the modulation index also becomes
double, the system is
(a) FM (b) AM
(c) PM (d) both FM and AM
Q20. The bandwidth requirement of a telephone channel is
(a) 3KHz (b) 5KHz
(c) 10KHz (d) 15KHz
Q21. In class A operation of an amplifier the current flows through the active device for
(a) whole of the input cycle
(b) half of the input cycle
(c) more than half of the input cycle
(d) more than three fourth of the input cycle
Q22. P Type Semiconductor material as a whole is
(a) positively charged (b) negatively charged
(c) electrically neutral (d) dipole
Q23. Hartley oscillator is
(a) an inductively coupled oscillator
(b) capacitor coupled oscillator
(c) switchable for low frequencies
(d) resistance coupled oscillator
Q24. h parameters of a transistor
(a) are constant
(b) vary with temperature
(c) are dependant upon collector current
(d) none of the above
Q25. The target cross section is changing, the best system for accurate tracking is
(a) monopulse (b) conical scanning
(c) sequential locking (d) lobe switching
Q26. Waveguides are not used for frequencies below
(a) 1GHz (b) 10 GHz
(c) 100 Ghz (d) 500 Mhz
Q27. The unit of magnetic susceptibility is
(a) Wb-m^2 (b) Wb A-m
(c) Wb/A-m (d) Wb/m^2
Q28. Schmitt trigger can be used as a
(a) comparator (b) square wave generator
(c) flip flop (d) all of these
Q29. For making a capacitor, it is better to select a dielectric having
(a) high permittivity (b) low permittivity
(c) same permittivity as that of air (d) very low permittivity
Q30. The value of resistor creating thermal noise is doubled .the noise power generated is
(a) halved (b) doubled (c) unchanged (d) tripled
Soln: Thermal noise or white noise power = kTB
where kT = N0 = PSD of thermal noise
B = bandwidth
as can be seen from the formula thermal noise power is independent of resistor value .
Q31. Subtracting 0101 from 1110 in binary terms, we get
(a) 0110 (b) 1010 (c) 1001 (d) 0011
Q32. The universal gate is
(a) AND (b) NOR
(c) XOR (d) NAND
Q33. Fidelity in a communication receiver is provided by
(a) mixer stage (b) detector stage
(c) various amplifier section (d) audio stage
Soln: Fidelity is the ability of the receiver to reproduce all the audio frequencies at the output .
Q34. The TWT is sometimes preferred to the magnetron as a radar transmitter outputtube because it is
(a) capable of a longer duty cycle (b) a more efficient amplifier
(c) more broadband (d) less noisy
Q35. Modulation system used for video modulation in tv transmission is
(a) DSB (b) VSB
(c) SSB (d) SSBSC
Q36. A yagi antenna produces
(a) eight pattern (b) broadside pattern
(c) end fire array (d) helical pattern
Q37. Medium frequency waves travel mainly as
(a) sky waves (b) surface waves
(c) space waves (d) ground wave
Q38. In a two cavity klystron , the input cavity resonator is also known as
(a) velocity modulator (b) catcher cavity
(c) buncher cavity (d) accelerator
Q39. When the gate of a P- channel junction field effect transistor is more positive, the draincurrent
(a) is increased (b) is reduced
(c) remains unaltered (d) decreases
Q40. Multiplication of 2 binary numbers A and B yields 11011; if A is 101 B is
(a) 101 (b) 111
(c) 110 (d) none of these
Q41. Which of the following can measure pressure directly?
(a) LVDT (b) strain guage
(c) Rotameter tube (d) bourdon tube
Q42. The binary code of (21.125)10 is
(a) 10101.001 (b) 10100.001
(c) 10101.010 (d) 10100.111
Q43. An op-amp zero crossing detector is basically_______converter
(a) sine to square wave (b) square to sine wave
(c) sine to sine wave (d) sine to triangle wave
Q44. Which of the following is not a 8 bit microprocessor
(a) INTEL8085 (b) MOTOROLA6800
(c) ZILOG280 (d) FAIRCHILD9440
Q45. _________is used for keeping oscillator frequency away from any drift
(a) PLL (b) VCO
(c) comparator (d) frequency synthesizer
Q46. __________ is also an active filter
(a) RC filter (b) notch filter
(c) butterworth filter (d) band pass filter
Q47. In 8085 microprocessor ------is the highest priority interupt
(a) INTR (b) RST5.5
(c) RST (d) trap
Q48. In the standard TTL the totem pole stage refers to
(a) the multi emitter I/p stage (b) phase splitter
(c) o/p buffer (d) open collector o/p stage
Q49. Decimal equivalent of hex no E5 is
(a) 279 (b) 229
(c) 427 (d) 3000
Q50. Crossover distortion does not occur in __________ amplifiers.
(a) push-pull (b) class-A
(c) class-B (d) class-AB
