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Electrical Questions And Answers Free Electrical interview questions for electrical alumni. Much of the time asked interview inquiries with answers under the subjects like electrical machines, Transmission and distribution, Power hardware and some broad essential questions. Why do not we employ RC or transformer coupling for extremely low frequencies (< 10 Hz) Ans. It is because, at such low frequencies (<10 Hz), the electrical and physical sizes of capacitors and transformers become too large. Why should coupling capacitors in transistor amplifiers possess high values Ans. A transistor amplifier (CE arrangement) has a low input impedance of the order of 500 Q or so. It is desired that reactance offered by the coupling capacitor should not be more than 20 9. To achieve this, large values of coupling capacitances must be used. Generally, the capacitance of coupling capacitors ranges from 1 ”F to 10 “F.  In a two-stage RC coupled amplifier; why are the capacitors required for the s

Why RC coupling very popular The RC coupling is very popular due to two basic reasons : (I) It employs inexpensive resistors and capacitors. (2) It provides constant voltage gain over the audio-frequency range. RC Coupled A Resistance Capacitance (RC) Coupled Amplifier is essentially a multi-organize enhancer circuit widely utilized in electronic circuits. Here the individual phases of the enhancer are associated together utilizing a resistor-capacitor mix because of which it bears its name as RC Coupled. Focal points of RC Coupled Amplifier Shabby, prudent, and minimized as it utilizes just resistors and capacitors. Offers a consistent addition over a wide recurrence band. Hindrances of RC Coupled Amplifier Unsatisfactory for low-recurrence intensification. Low voltage and power gain as the compelling burden opposition (and thus the increase) is diminished because of the way that the contribution of each stage exhibits low protection from its next stage. Dampness delicate, ma

Limitations of Terzaghi Theory The value of the coefficient of consolidation has been assumed to be constant.  The distance d of the drainage path cannot be measured accurately in the field. The thickness of the deposit is generally variable, and an average value has to be estimated.  There is sometimes difficulty 1n locating the drainage face, and sometimes thin previous seams that can act as good drainage faces are missed in the boring operations. The equation is based on the assumption that the consolidation is one-dimensional. In the field, the consolidation is generally 3-dimensional. The lateral drainage may have a significant effect on the time rate of consolidation. The initial consolidation and secondary consolidation have been neglected. Sometimes these form an important part of the total consolidation. In actual practice, the pressure distribution may be far from linear or uniform.

Epicyclic Gear Train An epicyclic gear train (otherwise called planetary gear) comprises of two gears mounted with the goal that the focal point of one gear spins around the focal point of the other. A bearer associates the focuses of the two gears and turns to convey one gear, called the planet gear or planet pinion, around the other, called the sun gear or sun wheel. If the axis of the shafts, over which the gear is compound mounted, are moving relative to the fixed axis, the gear train is known as an epicyclical gear train. In the simple, compound, and reverted gear train, the axis of the shafts is fixed. But in the epicyclic gear train, the shaft axis is not fixed but is moving relative to ' the fixed axis. Use of Epicyclic Gear Train The epicyclic gear trains are useful for transmitting high-velocity ratios with the gear of moderate size in a relatively lesser area. Epicyclic gear train works The working of the epicyclic gearbox can not be clarified quickly as it requires mor

Differential Gear of an automobile The differential gear used in the rear-drive of an automobile is shown in Fig.1 function is (a) to transmit motion from the engine shaft to the rear driving wheels. (b) To rotate the rear wheels at different speeds while the automobile 15 takes a turn. As long as the automobile 18 running on a straight path, the rear wheels are driven directly by the engine, and the speed of each of the wheels is the same. But when automobile 18 takes a turn, the outer wheel will run faster than the inner wheel because at that time the outer rear wheel has to cover more distance than the inner rear wheel. This is achieved by planet wheel train With bevel gears as shown in Fig. the bevel gear A (known as opinion) is keyed to the propeller shaft is driven from the engine shaft through ' universal coupling. This gear A drives the gear B (known as crown gear) that rotates freely on the shaft P.  Two equal gears C and D are mounted on 2 separate parts P and alphabetic

Mode Locking Mode Locking Lasers can be made to operate continuously or in pulses. As an example, the bandwidth of the 632.8 nm line in the He-Ne laser is 1.5 GHz, so that the shortest pulses that a He-Ne can produce would be 0.67. ns long. This is not particularly short by modem standards. Dye lasers typically have gain bandwidths greater than 10*1000000000000 Hz and can be used to generate pulses shorter than 100 fs. This is achieved by a technique called mode-locking. To achieve shorter laser pulses, mode locking of the laser modes is done Types of Mode Locking In a comparison of ultrafast and normal lasers, an ultrafast laser simultaneously lases in many different modes (the more the better), but the phases of the different modes are completely uncorrected. This will manufacture random (unpredictable) Fluctuations within the intensity over time. Mode locking describes the set of techniques that are used to generate a known correlation between the phases and therefore create it pos

RTOS Kernel Architecture For simpler applications, RTOS is usually a kernel but as complexity increases, various modules like networking protocol stacks debugging facilities, and a device I/Os are included in addition to the kernel. RTOS architecture diagram k (A) Kernel, RTOS kernel acts as an abstraction layer between the hardware and the applications. There are three broad categories of kernels (i) Monolithic kernel Monolithic kernels are part of Unix-like operating systems like Linux, F FreeBSD, etc. A monolithic kernel is one single program that contains all nine of the code necessary to perform each kernel-connected task. It runs all basic system services (i. e. process and memory management; interrupt handling and Input /Output communication, file system, etc) and provides powerful abstraction§ of the Underlying hardware. The amount of context switches and electronic communication concerning area unit is greatly reduced which makes it runs quicker than a microkernel. (ii) Microk