Multiple Choice Questions for Electronics Engineering Part 4
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Q.54 In a tunnel diode, electrons can tunnel through the P-N junction mainly because
- impurity level is low
- they have high energy
- barrier potential is very low
- depletion layer is extremely thin
Answer: 4
Q.55 Most of the transistors are NPN type and not PNP type because
- NPN transistor gives large voltage gain
- NPN transistors are more negative than PNP transistors
- In NPN transistor, the current conduction is by free electrons which are less obiles than holes
- We can have high conduction is NPN transistors
Answer: 4
Q.56 In a transistor
- Emitter is heavily doped while the collector moderately doped
- Collector base junction is forward biased
- Emitter is made wider than collector
- The input resistance is much larger than output resistance
Answer: 1
Q.57 If the instantaneous current in a ckt is given I = 2 cos t + amperes, the r. m. s. value of t current is
- 2 amp
- 2 amp
- 2 2 amp
- Zero amp
Answer: 2
Q.58 In an A. C. ckt, voltage and current are given V = 100 sin 100t volts i = 100 sin 10t + mA. The power dissipated in the ckt is
- 104 watts
- 10 watts
- 2.5 watts
- 5 watts
Answer: 3
Q.59 A 0.05 H-F capacitor charges through a resistor and is discharged through a resistor 20K . The time constant of the circuit is
- the same both during charging and discharging
- larger during charging process
- larger during discharging process
- none
Answer: 2
Q.60 The basic element of radio communica1 system which generates radio waves is
- micro phone
- transmitter
- transmitting antenna
- Loudspeaker
Answer: 2
Q.61 The input frequency of a bridge rectifier is 50 its output frequency will be
- 25 Hz
- 50 Hz
- 75 Hz
- 100 Hz
Answer: 4
Q.62 Which of the following voltage is used represent binary ‘1’ in digital circuits.
- 0 V
- 15 V
- + 5 V
- 25 V
Answer: 3
Q.63 Hexadecimal number system is used as hand language for representing
- decimal number
- binary number
- octal number
- all the above
Answer: 2
Q.64 Logic state 0 in positive logic corresponds to
- zero voltage
- positive voltage
- higher voltage level
- lower voltage level
Q.65 The o⟋p of a 2 - input OR gate is 1 when its
- both inputs are 1
- both inputs are 0
- either input is 1
- either input is 0
Answer: 3
Q.66 TTL logic family is most popularly used industries because it
- provides greater operating speed
- has a good fan in & fan out
- has easy interface with other digital circuitry
- all the above
Answer: 2
Q.67 Transformer cores are laminated in order to
- simplify its construction
- minimise eddy current loss
- reduce cost
- reduce hysteresis loss
Answer: 2
Q.68 The external characteristic of a shunt generator can be obtained directly from its – characteristic
- internal
- open-circuit
- load-saturation
- performance
Answer: 2
Q.69 Load saturation characteristic of a d. c. generator gives relation between
- V and Ia
- E and Ia
- E0 and If
- V and If
Answer: 4
Q.70 The biggest advantage of T-T connection over the V-V connection of 3-phase power transformation is that it provides.
- a set of balanced voltages under load
- a true 3-phase, 4-wire system
- a higher ratio of utilization
- more voltages
Answer: 3
Q.71 The biggest advantage of T-T connection over the V-V connection of 3-phase power transformation is that it provides.
- a set of balanced voltages under load
- a true 3-phase, 4-wire system
- a higher ratio of utilization
- more voltages
Answer: 2
Q.72 U. H. F. band covers the range of
- 0 - 300 KHz
- 3 - 30 MHz
- 300 - 3000 KHz
- 300 MHz - 3 GHz
Answer: 4
Q.73 The ripple factor of a bridge rectifier is
- 0.48
- 0.812
- 1.11
- 1.21
Answer: 1
Q.74 The high level language is⟋are
- Machine language
- BASIC
- Assembly language
- PASCAL
Answer: 2,4
Q.75 The high level language can be translated into machine language with the help of
- Assembler
- Stack pointer
- Compiler
- Multiplexer
Answer: 3
Q.76 In the emitter characteristic of UJT, the negative resistance portion.
- lies in the cut-off region
- continues up to peak point
- lasts until the valley point is reached
- does not exist
Answer: 3
Q.77 After firing as SCR, the gating pulse is removed. The current in the SCR will
- remain the same
- immediately fall to zero
- rise up
- None
Answer: 1
Q.78 When reverse bias is applied to a junction diode, it
- Increases the potential barrier
- Decreases the potential barrier
- greatly increases the minority carrier current
- greatly increases the majority carrier current
Answer: 1
Q.79 Transformer cores are laminated in order to
- simplify its construction
- minimise eddy current loss
- reduce cost
- reduce hysteresis loss
Answer: 2
Q.80 When a P – N junction is forward biased
- Only electrons in N-region are injected into P-region
- Only holes in P-region are injected into N-region
- Majority carriers in each region are injected into the other region
- Minority current is reduced to zero
Answer: 3