# Important Questions on Diploma Electronics Engineering

1. In case of RC driving point function
(a) ZRC cannot have a pole at infinity
(b) ZRC cannot have a pole at origin
(c) YRC cannot have a pole at infinity
(d) ZRC and YRC are constant or zero at infinity

2. A Hurwitz polynomial has
(a) zeros only in the left half plane
(b) poles only in the left half plane
(c) zeros anywhere in the S Plane
(d) poles on the jw axis only

3. If ( wL << R ) and ( wC << G ) of a transmission line, the attenuation constant γ is
(a) proportional to frequency
(b) inversely proportional to frequency
(c) independent of frequency
(d) none of these

4. The distortionless condition of a transmission line is given by
(a) Z0 = √(L/C)
(b) RG = LC
(c) R/G = L/C
(d) none of these

5. If k = 0 in a transmission line, the VSWR is given by
(a) 2
(b) 1
(c) 3
(d) ∞

6. For the short circuit load, the voltage minimum occurs at
(a) source point
(d) none of these

7. In insulators
(a) EM waves propagate
(b) current flows
(c) electrostatic energy is stored
(d) magnetic energy is stored

8. The Hall co-efficient has the unit of
(a) c/m3
(b) m3/c
(c) c3/m
(d) c/m

9. Forbidden gap in a semiconductor is
(a) Large
(b) very large
(c) small
(d) not present

10. Diode is used as
(a) current source
(b) voltage source
(c) amplifier
(d) rectifier

11. For the lower Q-point operation of a diode ac resistance is
(a) High
(b) Low
(c) very low
(d) reduced

12. The reverse saturation current of a diode means
(a) the current under reverse bias
(b) saturated current in forward bias
(c) highest current

13. At room temperature, the thermal voltage in a diode is
(a) 26V
(b) 26mV
(c) 2.6V
(d) 2.6mV

14. The knee voltage of GaAs is
(a) 0.3V
(b) 0.7V
(c) 1.2V
(d) 2.3V

15. The reverse saturation current of a silicon diode doubles for every
(a) 10ºK rise in temperature
(b) 10ºC rise in temperature
(c) 2ºC rise in temperature
(d) 10ºF rise in temperature

16. If the current in a diode is 10mA at forward bias voltage of 0.1V, the static resistance is
(a) 10Ω
(b) 100Ω
(c) 1kΩ
(d) 0.01Ω

17. For low frequency operated diode, the effects of diffusion capacitance is
(a) Negligible
(b) High
(c) more than transition capacitance
(d) less than transition capacitance

18. A.C. resistance of a diode means
(a) static resistance
(b) dynamic resistance
(c) it does not change with V-I characteristic
(d) constant resistance

19. In the break down region of a zener diode
(a) current is zero
(b) current is very high
(c) voltage is zero
(d) current is very small

20. Power diode are used with
(a) heat sinks
(b) reverse bias
(c) forward bias
(d) at room temperature

21. Tunnel diode is used in
(a) Oscillators
(b) Amplifiers
(c) Regulators
(d) switching circuits

22. An a.c. regulator can be designed with
(a) two diodes
(b) two tunnel diodes
(c) two zener diodes
(d) none of these

23. The diodes are used in series to
(a) increase current carrying capacity
(b) increase PIV
(c) reduce PIV
(d) reduce resistance

24. If ID = 10mA at VD = 1V at a point of operation, then maximum power dissipation is
(a) 1.0mW
(b) 1.0 W
(c) 0.1mW
(d) 10mW

25. In bridge rectifier PIV of each diode needs to be
(a) 4Vm
(b) 2Vm
(c) Vm
(d) Vm/4

## More Question Set on Electronics Engineering Diploma MCQs from Various Exam

 Model Question Old Question Sample Papers Mock Test Practice Set Question Bank Important Questions Test Papers Typical Questions Selected Questions

26. In half wave rectifier, if Vi to the diode is 20sin(wt), Vdc is
(a) 6.37V
(b) 10V
(c) 14.2V
(d) 20V

27. In active region of common base transistor
(a) B-E junction is forward biased
(b) B-E junction is reverse biased
(c) C-B junction is forward biased
(d) both junctions are reverse biased

28. The maximum power dissipated by a diode is
(a) VDID
(b) VrIr
(c) VDID + VrIr
(d) zero

29. In which of the following device reverse recovery time is nearly zero?
(a) Diode
(b) tunnel diode
(c) Schottky diode
(d) PIN diode

30. Two similar mutually coupled coils have a total inductance of 900mH and co-efficient of coupling is 0.5. The self inductance of each coil is
(a) 300mH
(b) 150mH
(c) 75mH
(d) 50mH

31. Common collector transistor configuration is used for
(a) voltage amplification
(b) current amplification
(c) impedance matching
(d) rectification

32. Stability factor S of a self bias circuit depends on
(a) β alone
(b) β, Rb and Re
(c) β, Rb and Rc
(d) Rb and Rc

33. Hybrid parameters equivalent for BJT is valid at
(a) low frequency
(b) HF
(c) VHF
(d) UHF

34. Voltage gain of BJT amplifier is
(a) AIRL
(b) AI (Ri/RL)
(c) A (RL/Ri)
(d) none of these

35. The relation between ID and VGS in FET is
(a) ID = IDSS ( 1 – VGS/ VP )
(b) ID = IDSS ( 1 – VGS/ VP )2
(c) ID = IDSS ( VGS/ VP )
(d) ID = IDSS ( 1 – VP/ VGS )

36. If VP = 5V, the maximum drain current, the dc resistance is
(a) 25Ω
(b) 25KΩ
(c) 250Ω
(d) 250KΩ

37. The pinch off voltage is
(a) VDS (max) of flat drain curve
(b) VDS (min) of flat drain curve
(c) VDS at VGS = 0V
(d) VDS at VGS < 0V

38. If IDSS = 7mA, VGS (off) = 3V and VGS = – 1V then the drain current is
(a) 31.2mA
(b) 312mA
(c) 3.11mA
(d) 0.312mA

39. If the transconductance of MOSFET is 10 mmho and its drain resistance is 3KΩ, its voltage gain is
(a) 0.3
(b) 3
(c) 3.3
(d) 30

40. gm of MOSFET is controlled by
(a) gate-source voltage
(b) drain- source voltage
(c) drain current
(d) gate current

41. MOSFET is used for
(a) regulator control
(b) maintaining constant voltage
(c) automatic gain control
(d) low input impedance

42. SCR can be used in
(a) Oscillator
(b) Regulator
(c) Amplifier
(d) light dimming

43. The drain resistance of JFET is
(a) 1/ gm
(b) μ /gm
(c) gm /μ
(d) μ gm

44. For 1 Volt emitter bias what is RE if IE = 300mA
(a) 1Ω
(b) 3.33Ω
(c) 6.667Ω
(d) 33.3Ω

45. Torque/weight ratio of an instrument indicates
(a) selectivity
(b) accuracy
(c) sensitivity
(d) fidelity

46. The first order instrument is characterized by
(a) time constant only
(b) static sensitivity and time constant
(c) static sensitivity and damping co-efficient
(d) static sensitivity and natural frequency of oscillations

47. Which one of the following decides the time of response of an indicating instrument?
(a) deflecting system
(b) controlling system
(c) damping system
(d) pivot and jewel system

48. The difference between the indicated value and the true value of a quantity is
(a) gross error
(b) absolute error
(c) dynamic error
(d) relative error

49. A wattmeter has a range of 1000W with an error of ±1% of full scale deflection, If the true power passed through it is 100W, the relative error would be
(a) ±10%
(b) ±5%
(c) ±1%
(d) ±0.5%

50. To reduce the effect of noise level, 100 sets of data are arranged. The arranged data set will have a noise level reduced by a factor of
(a) 10
(b) 10√2
(c) 50√2
(d) 100