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50 questions of 150 points with answer key

AFCAT Mock Test 2021 EKT-Electronic Science (for technical candidates): The AFCAT (1) 2021 exam will be conducted in online mode by the Indian Air Force (IAF) at various examination centers from February 20-21, 2021. The AFCAT Engineering Knowledge Test (EKT) will be conducted for 150-point technical candidates (50 questions of 3 marks each) in addition to the AFCAT exam of 300 marks (100 Questions of 3 marks each) in online mode. Here, candidates can attempt the AFCAT EKT mock test of electronic science subject according to the latest exam pattern and the latest curriculum.

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AFCAT 2021 EKT Electronic Science Mock Test (for technical candidates): online exam – 50 questions of 150 points

Q1. If x = a (cost t + t sin t), y = a (sin t – t cost t). The value of dy / dx is

(a cost

(b) sin t

(c) tan t

(d) sec2 t

Q2. The area of ​​the three faces of a cuboid is in the ratio 2: 3: 4 and its volume is 9000 cm3. The length of the shortest edge is

(a) 15 cm

(b) 30 cm

(c) 20 cm

(d) 60 cm

Q4. Tickets numbered 1 to 20 are mixed and then one ticket is drawn. What is the probability that the ticket drawn has a number multiple of 3 or 5?

(a) 8/2

(b) 9/20

(c) 15/8

(d) 2/20

Q5. The projection of a vector on another vector is

(a) Scalar

(b) Vector

(c) neither vector nor scalar

(d) either scalar or vector

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Q6. In the MKS system we measure

(a) mass in kilograms

(b) distance in meters

(c) time in seconds

(d) all these

Q7. When the separation between two charges is made four times, the force between them

(a) increase four times

(b) decrease four times

(c) increase sixteen times

(d) decrease sixteen times

Q8. When a conductor cuts off the magnetic flux, an electromotive force is induced in the conductor. This is known as

(a) Joule’s law

(c) Coulomb’s law

(d) Ampère’s law

Q9. X-rays are used for the study of crystal structure because

(a) X-rays are completely absorbed by the crystal

(b) the wavelength of the x-rays is of the same order of magnitude in the inter-atomic spacing in the crystals

(c) the wavelength of x-rays is very small compared to the inter-atomic spacing in crystals

(d) the crystals are completely transparent to x-rays

Q10. A radioactive isotope has a half-life of 10 days. If 125 g remains today, what was its original weight 40 days earlier?

(a) 600 g

(b) 1000 g

(c) 1250 g

(d) 2000 g

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Q11. Angles project actual size only when the plane containing the angle and the projection plane are

(a) Aligned

(c) Perpendicular

(d) Parallel

Q12. Tesla is a measure of

(a) magnetic flux density

(b) electric flux density

(c) magnetic potential

(d) electric potential

(a) susceptibility

(b) impedance

(c) reactance

(d) conductance

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Q14. _________ is an active filter

(a) RC filter

(b) notch filter

(c) Butterworth filter

(d) band pass filter

Q15. For the adaptation of the load of the transmission line over a range of frequencies, it is preferable to use a

(a) Balun

(c) double heel

(d) single heel

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Q16. The emitter follower is used for

(a) reduce the gain

(b) increase the distortion

(c) impedance matching

(d) none of these

Q17. Binary equivalent of (45)ten is

(a) (11101)2

(b) (11110)2

(c) (101101)2

(d) (110101)2

Q18. In the size of computer memory, K indicates the kilogram, which is equal to

(a) 1000

(b) 1024

(c) 100

(d) 10,000

Q19. An astable multivibrator has

(b) a stable state

(c) three stable states

(d) two stable states

Q20. An ideal op amp has

(a) infinite input and output impedance

(b) very low input and output impedance

(c) low input impedance and very high output impedance

(d) infinite input impedance and zero output impedance

Q21. An instruction used to set the hold flag in a computer can be classified as a

(a) data transfer instruction

(b) arithmetic instruction

(c) logic instruction

(d) program control instruction

Q22. A FET is a

(a) bipolar semiconductor device

(b) unipolar semiconductor device

(c) non-semiconductor device

(d) both (a) and (c)

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Q23. For Gunn diodes, the preferred semiconductor material is

(a) Silicon

(b) Germanium

(c) gallium arsenide

(d) all these

Q24. In a JFET, the drain current is maximum when VGS is

(to zero

(b) negative

(c) positive

(d) equal to Vp

Q25. The laser output is

(a) Infrared

(b) polarized

(c) narrow beam

(d) consistent

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Q26. Compared to a closed loop system, an open loop system is

(a) more stable and more precise

(b) less stable and less precise

(c) more stable but less precise

(d) less stable but more precise

Q27. The transfer function of a system is used to calculate

(b) the time constant

(c) the order of the system

(d) the output for a given input

Q28. In a closed loop control system

(a) the control action depends on the output and also on the input command

(b) the output signal is returned for comparison with the reference signal

(c) accuracy is better than in open loop system

(All the foregoing

Q29. The difference between the reference input and the actual output signal is called

(a) error signal

(b) control signal

(c) actuation signal

(d) transfer function

Q30. If the transfer function of a system is 1 / Ts + 1, the steady state error on the single step input is

(at

(b) zero

(c) infinite

(d) none of these

Q31. In a PID controller, the values ​​of proportional, integral and derivative depend on

(a) future, past and present errors respectively

(b) present, past and future errors respectively

(c) past, present and future errors respectively

(d) present, future and past errors respectively

Q32. The inverse Laplace transform of 2 / s + 1 is

(a) 2 (t + 1)

(b) 2nd-t

(c) 2ndt

(d) e-2t

Q33. The signal is extended from 96KHz to 100KHz, so the minimum required sample rate is

(a) 8KHz

(b) 200KHz

(c) 4KHz

(d) 100KHz

Q34. A differentiation circuit has a

(a) very high time constant

(b) very low time constant

(c) infinite time constant

(d) zero time constant

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Q35. Ideally, the voltage standing wave ratio (VSWR) should be

(a) as large as possible

(b) as small as possible

(c) as close to unity as possible

(d) infinity

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Q36. The following is / are property (s) of quantization

(a) it is a nonlinear process

(b) it is an irreversible process

(c) it maps a larger set of input values ​​to a smaller set

(d) all these

Q37. The most common filters used in the SSB generation are

(a) mechanical filters

(b) RC filters

(c) LC filters

(d) low pass filters

Q38. If the antenna diameter of a radar system is increased by a factor of 4, the maximum range will be increased by a factor of

(a) 2

(b) 4

(c) 8

(d) 16

Q39. The following type of multiplexing cannot be used for analog signaling

(a) FDM

(b) GDT

(c) CDM

(d) None of these

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Q40. In TDM systems, channel separation is done using

(a) AND gates

(b) band pass filters

(c) differentiator circuit

(d) integrator circuit

Q41. The OSI model data link layer specifies

(a) data link procedures which provide for the exchange of data via frames that can be sent and received

(b) the interface between the X.25 network and the packet device

(c) the virtual circuit interface to the packet switched service

(All the foregoing

Q42. FDDI is a

(a) ring network

(b) star network

(c) mesh network

(d) bus network

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Q43. Which of the following TCP / IP protocols allows an application program on one machine to send a datagram to an application program on another machine?

(a) UDP

(b) VMTP

(c) X.25

(d) SMTP

Q44. The main difference between synchronous and asynchronous transmission is that

(a) the synchronization is derived from the data in synchronous transmission

(b) synchronization is mixed with data in asynchronous transmission

(c) the pulse height is different

(d) the required bandwidth is different

Q45. The transducer is a device that

(a) converts one form of power into another

(b) is similar to transformer

(c) convert one form of energy into another

(d) helps to measure electricity

Q46. The hysteresis principle is not used in

(a) electric water geyser

(b) electric motor

(c) multi-vibrators

(d) Schmitt trigger

Q47. Which of the following motors would not be suitable for use as servo motors?

(a) AC induction motor

(b) brushless AC motor

(c) stepper motor

(d) permanent magnet direct current motor

Q48. The stator of an induction motor is made up of

(a) carbon

(b) wood

(c) copper prints

(d) silicon steel laminators

Q49. An ideal DC generator is one that has voltage regulation _____

(low

(b) high

(c) zero

(d) positive

Q50. The switch is used in

(a) Direct current generator

(b) Alternating current generator

(c) inverters

(d) converters

 Answer key for the AFCAT EKT electronic science simulation test Question Reply Question Reply 1 VS 26 VS 2 A 27 re 3 B 28 re 4 B 29 A 5 A 30 B 6 re 31 B 7 re 32 B 8 B 33 B 9 B 34 B ten re 35 VS 11 re 36 re 12 A 37 A 13 B 38 A 14 VS 39 B 15 VS 40 A 16 VS 41 A 17 VS 42 A 18 B 43 A 19 A 44 B 20 re 45 VS 21 VS 46 VS 22 B 47 VS 23 VS 48 re 24 A 49 VS 25 re 50 A 